diff --git a/cura/Machines/ContainerTree.py b/cura/Machines/ContainerTree.py
index 2f641973ac..ca24950c78 100644
--- a/cura/Machines/ContainerTree.py
+++ b/cura/Machines/ContainerTree.py
@@ -5,10 +5,15 @@ from UM.Logger import Logger
 from UM.Settings.ContainerRegistry import ContainerRegistry  # To listen to containers being added.
 from UM.Settings.DefinitionContainer import DefinitionContainer
 from UM.Settings.Interfaces import ContainerInterface
+import cura.CuraApplication  # Imported like this to prevent circular dependencies.
 from cura.Machines.MachineNode import MachineNode
 
-from typing import Dict
+from typing import Dict, List, TYPE_CHECKING
 import time
+
+if TYPE_CHECKING:
+    from cura.Machines.QualityGroup import QualityGroup
+
 ##  This class contains a look-up tree for which containers are available at
 #   which stages of configuration.
 #
@@ -29,6 +34,21 @@ class ContainerTree:
         container_registry.containerAdded.connect(self._machineAdded)
         self._loadAll()
 
+    ##  Get the quality groups available for the currently activated printer.
+    #
+    #   This contains all quality groups, enabled or disabled. To check whether
+    #   the quality group can be activated, test for the
+    #   ``QualityGroup.is_available`` property.
+    #   \return For every quality type, one quality group.
+    def getCurrentQualityGroups(self) -> Dict[str, "QualityGroup"]:
+        global_stack = cura.CuraApplication.CuraApplication.getInstance().getGlobalContainerStack()
+        if global_stack is None:
+            return {}
+        variant_names = [extruder.variant.getName() for extruder in global_stack.extruders.values()]
+        material_bases = [extruder.material.getMetaDataEntry("base_file") for extruder in global_stack.extruders.values()]
+        extruder_enabled = [extruder.isEnabled for extruder in global_stack.extruders.values()]
+        return self.machines[global_stack.definition.getId()].getQualityGroups(variant_names, material_bases, extruder_enabled)
+
     ##  Builds the initial container tree.
     def _loadAll(self):
         Logger.log("i", "Building container tree.")
diff --git a/cura/Machines/MachineNode.py b/cura/Machines/MachineNode.py
index b474ae94bd..f0a001b2d6 100644
--- a/cura/Machines/MachineNode.py
+++ b/cura/Machines/MachineNode.py
@@ -1,19 +1,16 @@
 # Copyright (c) 2019 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
 
-from typing import TYPE_CHECKING
+from typing import Dict, List
 
 from UM.Logger import Logger
 from UM.Util import parseBool
 from UM.Settings.ContainerRegistry import ContainerRegistry  # To find all the variants for this machine.
-from UM.Settings.Interfaces import ContainerInterface
 from cura.Machines.ContainerNode import ContainerNode
+from cura.Machines.QualityGroup import QualityGroup  # To construct groups of quality profiles that belong together.
 from cura.Machines.QualityNode import QualityNode
 from cura.Machines.VariantNode import VariantNode
 
-if TYPE_CHECKING:
-    from typing import Dict
-
 ##  This class represents a machine in the container tree.
 #
 #   The subnodes of these nodes are variants.
@@ -36,10 +33,57 @@ class MachineNode(ContainerNode):
         self.quality_definition = my_metadata.get("quality_definition", container_id)
         self.exclude_materials = my_metadata.get("exclude_materials", [])
         self.preferred_variant_name = my_metadata.get("preferred_variant_name", "")
+        self.preferred_quality_type = my_metadata.get("preferred_quality_type", "")
 
-        container_registry.containerAdded.connect(self._variantAdded)
         self._loadAll()
 
+    ##  Get the available quality groups for this machine.
+    #
+    #   This returns all quality groups, regardless of whether they are
+    #   available to the combination of extruders or not. On the resulting
+    #   quality groups, the is_available property is set to indicate whether the
+    #   quality group can be selected according to the combination of extruders
+    #   in the parameters.
+    #   \param variant_names The names of the variants loaded in each extruder.
+    #   \param material_bases The base file names of the materials loaded in
+    #   each extruder.
+    #   \param extruder_enabled Whether or not the extruders are enabled. This
+    #   allows the function to set the is_available properly.
+    #   \return For each available quality type, a QualityGroup instance.
+    def getQualityGroups(self, variant_names: List[str], material_bases: List[str], extruder_enabled: List[bool]) -> Dict[str, QualityGroup]:
+        if len(variant_names) != len(material_bases) or len(variant_names) != len(extruder_enabled):
+            Logger.log("e", "The number of extruders in the list of variants (" + str(len(variant_names)) + ") is not equal to the number of extruders in the list of materials (" + str(len(material_bases)) + ") or the list of enabled extruders (" + str(len(extruder_enabled)) + ").")
+            return {}
+        # For each extruder, find which quality profiles are available. Later we'll intersect the quality types.
+        qualities_per_type_per_extruder = [{} for _ in range(len(variant_names))]  # type: List[Dict[str, QualityNode]]
+        for extruder_nr, variant_name in enumerate(variant_names):
+            if not extruder_enabled[extruder_nr]:
+                continue  # No qualities are available in this extruder. It'll get skipped when calculating the available quality types.
+            material_base = material_bases[extruder_nr]
+            if variant_name not in self.variants or material_base not in self.variants[variant_name].materials:
+                # The printer has no variant/material-specific quality profiles. Use the global quality profiles.
+                qualities_per_type_per_extruder[extruder_nr] = self.global_qualities
+            else:
+                # Use the actually specialised quality profiles.
+                qualities_per_type_per_extruder[extruder_nr] = self.variants[variant_name].materials[material_base].qualities
+
+        # Create the quality group for each available type.
+        quality_groups = {}
+        for quality_type, global_quality_node in self.global_qualities.items():
+            quality_groups[quality_type] = QualityGroup(name = global_quality_node.getMetaDataEntry("name", "Unnamed profile"), quality_type = quality_type)
+            quality_groups[quality_type].node_for_global = global_quality_node
+            for extruder, qualities_per_type in qualities_per_type_per_extruder:
+                quality_groups[quality_type].nodes_for_extruders[extruder] = qualities_per_type[quality_type]
+
+        available_quality_types = set(quality_groups.keys())
+        for extruder_nr, qualities_per_type in enumerate(qualities_per_type_per_extruder):
+            if not extruder_enabled[extruder_nr]:
+                continue
+            available_quality_types.intersection_update(qualities_per_type.keys())
+        for quality_type in available_quality_types:
+            quality_groups[quality_type].is_available = True
+        return quality_groups
+
     ##  (Re)loads all variants under this printer.
     def _loadAll(self):
         # Find all the variants for this definition ID.
@@ -55,19 +99,4 @@ class MachineNode(ContainerNode):
         if len(global_qualities) == 0:  # This printer doesn't override the global qualities.
             global_qualities = container_registry.findInstanceContainersMetadata(type = "quality", definition = "fdmprinter", global_quality = True)  # Otherwise pick the global global qualities.
         for global_quality in global_qualities:
-            self.global_qualities[global_quality["quality_type"]] = QualityNode(global_quality["id"], parent = self)
-
-    ##  When a variant gets added to the set of profiles, we need to update our
-    #   tree here.
-    def _variantAdded(self, container: ContainerInterface):
-        if container.getMetaDataEntry("type") != "variant":
-            return  # Not interested.
-        name = container.getMetaDataEntry("name")
-        if name in self.variants:
-            return  # Already have this one.
-        if container.getMetaDataEntry("hardware_type") != "nozzle":
-            return  # Only want nozzles in my tree.
-        if container.getMetaDataEntry("definition") != self.container_id:
-            return  # Not a nozzle that fits in my machine.
-
-        self.variants[name] = VariantNode(container.getId(), machine = self)
\ No newline at end of file
+            self.global_qualities[global_quality["quality_type"]] = QualityNode(global_quality["id"], parent = self)
\ No newline at end of file
diff --git a/cura/Machines/MaterialManager.py b/cura/Machines/MaterialManager.py
index bbe305a01b..4790314b25 100644
--- a/cura/Machines/MaterialManager.py
+++ b/cura/Machines/MaterialManager.py
@@ -59,15 +59,6 @@ class MaterialManager(QObject):
         # Root_material_id -> MaterialGroup
         self._material_group_map = dict()  # type: Dict[str, MaterialGroup]
 
-        # Approximate diameter str
-        self._diameter_machine_nozzle_buildplate_material_map = dict()  # type: Dict[str, Dict[str, MaterialNode]]
-
-        # We're using these two maps to convert between the specific diameter material id and the generic material id
-        # because the generic material ids are used in qualities and definitions, while the specific diameter material is meant
-        # i.e. generic_pla -> generic_pla_175
-        # root_material_id -> approximate diameter str -> root_material_id for that diameter
-        self._material_diameter_map = defaultdict(dict)  # type: Dict[str, Dict[str, str]]
-
         # Material id including diameter (generic_pla_175) -> material root id (generic_pla)
         self._diameter_material_map = dict()  # type: Dict[str, str]
 
@@ -75,11 +66,6 @@ class MaterialManager(QObject):
         # GUID -> a list of material_groups
         self._guid_material_groups_map = defaultdict(list)  # type: Dict[str, List[MaterialGroup]]
 
-        # The machine definition ID for the non-machine-specific materials.
-        # This is used as the last fallback option if the given machine-specific material(s) cannot be found.
-        self._default_machine_definition_id = "fdmprinter"
-        self._default_approximate_diameter_for_quality_search = "3"
-
         self._favorites = set(cura.CuraApplication.CuraApplication.getInstance().getPreferences().getValue("cura/favorite_materials").split(";"))
         self.materialsUpdated.emit()
 
@@ -87,7 +73,15 @@ class MaterialManager(QObject):
         return self._material_group_map.get(root_material_id)
 
     def getRootMaterialIDForDiameter(self, root_material_id: str, approximate_diameter: str) -> str:
-        return self._material_diameter_map.get(root_material_id, {}).get(approximate_diameter, root_material_id)
+        original_material = CuraContainerRegistry.getInstance().findInstanceContainersMetadata(id=root_material_id)[0]
+        if original_material["approximate_diameter"] == approximate_diameter:
+            return root_material_id
+
+        matching_materials = CuraContainerRegistry.getInstance().findInstanceContainersMetadata(type = "material", brand = original_material["brand"], definition = original_material["definition"], material = original_material["material"], color_name = original_material["color_name"])
+        for material in matching_materials:
+            if material["approximate_diameter"] == approximate_diameter:
+                return material["id"]
+        return root_material_id
 
     def getRootMaterialIDWithoutDiameter(self, root_material_id: str) -> str:
         return self._diameter_material_map.get(root_material_id, "")
@@ -109,13 +103,16 @@ class MaterialManager(QObject):
     # A convenience function to get available materials for the given machine with the extruder position.
     #
     def getAvailableMaterialsForMachineExtruder(self, machine: "GlobalStack",
-                                                extruder_stack: "ExtruderStack") -> Optional[Dict[str, MaterialNode]]:
+                                                extruder_stack: "ExtruderStack") -> Dict[str, MaterialNode]:
         nozzle_name = None
         if extruder_stack.variant.getId() != "empty_variant":
             nozzle_name = extruder_stack.variant.getName()
 
         # Fetch the available materials (ContainerNode) for the current active machine and extruder setup.
-        return self.getAvailableMaterials(machine.definition.getId(), nozzle_name)
+        materials =self.getAvailableMaterials(machine.definition.getId(), nozzle_name)
+        compatible_material_diameter = str(round(extruder_stack.getCompatibleMaterialDiameter()))
+
+        return {key: material for key, material in materials.items() if material.getMetaDataEntry("approximate_diameter") == compatible_material_diameter}
 
     #
     # Gets MaterialNode for the given extruder and machine with the given material name.
@@ -152,27 +149,10 @@ class MaterialManager(QObject):
     #
     def getMaterialNodeByType(self, global_stack: "GlobalStack", position: str, nozzle_name: str,
                               buildplate_name: Optional[str], material_guid: str) -> Optional["MaterialNode"]:
-        node = None
         machine_definition = global_stack.definition
-        extruder_definition = global_stack.extruders[position].definition
-        if parseBool(machine_definition.getMetaDataEntry("has_materials", False)):
-            material_diameter = extruder_definition.getProperty("material_diameter", "value")
-            if isinstance(material_diameter, SettingFunction):
-                material_diameter = material_diameter(global_stack)
+        variant_name = global_stack.extruders[position].variant.getName()
 
-            # Look at the guid to material dictionary
-            root_material_id = None
-            for material_group in self._guid_material_groups_map[material_guid]:
-                root_material_id = cast(str, material_group.root_material_node.getMetaDataEntry("id", ""))
-                break
-
-            if not root_material_id:
-                Logger.log("i", "Cannot find materials with guid [%s] ", material_guid)
-                return None
-
-            node = self.getMaterialNode(machine_definition.getId(), nozzle_name, buildplate_name,
-                                        material_diameter, root_material_id)
-        return node
+        return self.getMaterialNode(machine_definition.getId(), variant_name, buildplate_name, 3, material_guid)
 
     #   There are 2 ways to get fallback materials;
     #   - A fallback by type (@sa getFallbackMaterialIdByMaterialType), which adds the generic version of this material
@@ -254,41 +234,21 @@ class MaterialManager(QObject):
         return node
 
     def removeMaterialByRootId(self, root_material_id: str):
-        material_group = self.getMaterialGroup(root_material_id)
-        if not material_group:
-            Logger.log("i", "Unable to remove the material with id %s, because it doesn't exist.", root_material_id)
-            return
-
         container_registry = CuraContainerRegistry.getInstance()
-        nodes_to_remove = [material_group.root_material_node] + material_group.derived_material_node_list
-        # Sort all nodes with respect to the container ID lengths in the ascending order so the base material container
-        # will be the first one to be removed. We need to do this to ensure that all containers get loaded & deleted.
-        nodes_to_remove = sorted(nodes_to_remove, key = lambda x: len(x.getMetaDataEntry("id", "")))
-        # Try to load all containers first. If there is any faulty ones, they will be put into the faulty container
-        # list, so removeContainer() can ignore those ones.
-        for node in nodes_to_remove:
-            container_id = node.getMetaDataEntry("id", "")
-            results = container_registry.findContainers(id = container_id)
-            if not results:
-                container_registry.addWrongContainerId(container_id)
-        for node in nodes_to_remove:
-            container_registry.removeContainer(node.getMetaDataEntry("id", ""))
+        results = container_registry.findContainers(id=root_material_id)
+        if not results:
+            container_registry.addWrongContainerId(root_material_id)
+
+        for result in results:
+            container_registry.removeContainer(result.getMetaDataEntry("id", ""))
 
-    #
-    # Methods for GUI
-    #
     @pyqtSlot("QVariant", result=bool)
     def canMaterialBeRemoved(self, material_node: "MaterialNode"):
         # Check if the material is active in any extruder train. In that case, the material shouldn't be removed!
         # In the future we might enable this again, but right now, it's causing a ton of issues if we do (since it
         # corrupts the configuration)
         root_material_id = material_node.getMetaDataEntry("base_file")
-        material_group = self.getMaterialGroup(root_material_id)
-        if not material_group:
-            return False
-
-        nodes_to_remove = [material_group.root_material_node] + material_group.derived_material_node_list
-        ids_to_remove = [node.getMetaDataEntry("id", "") for node in nodes_to_remove]
+        ids_to_remove = [metadata.get("id", "") for metadata in CuraContainerRegistry.getInstance().findInstanceContainersMetadata(base_file=root_material_id)]
 
         for extruder_stack in CuraContainerRegistry.getInstance().findContainerStacks(type = "extruder_train"):
             if extruder_stack.material.getId() in ids_to_remove:
@@ -303,38 +263,24 @@ class MaterialManager(QObject):
         if CuraContainerRegistry.getInstance().isReadOnly(root_material_id):
             Logger.log("w", "Cannot set name of read-only container %s.", root_material_id)
             return
+        containers = CuraContainerRegistry.getInstance().findInstanceContainers(id = root_material_id)
+        containers[0].setName(name)
 
-        material_group = self.getMaterialGroup(root_material_id)
-        if material_group:
-            container = material_group.root_material_node.container
-            if container:
-                container.setName(name)
-
-    #
-    # Removes the given material.
-    #
     @pyqtSlot("QVariant")
     def removeMaterial(self, material_node: "MaterialNode") -> None:
         root_material_id = material_node.getMetaDataEntry("base_file")
         if root_material_id is not None:
             self.removeMaterialByRootId(root_material_id)
 
-    #
-    # Creates a duplicate of a material, which has the same GUID and base_file metadata.
-    # Returns the root material ID of the duplicated material if successful.
-    #
-    @pyqtSlot("QVariant", result = str)
-    def duplicateMaterial(self, material_node: MaterialNode, new_base_id: Optional[str] = None, new_metadata: Dict[str, Any] = None) -> Optional[str]:
-        root_material_id = cast(str, material_node.getMetaDataEntry("base_file", ""))
+    def duplicateMaterialByRootId(self, root_material_id,  new_base_id: Optional[str] = None, new_metadata: Dict[str, Any] = None) -> Optional[str]:
+        container_registry = CuraContainerRegistry.getInstance()
+        results = container_registry.findContainers(id=root_material_id)
 
-        material_group = self.getMaterialGroup(root_material_id)
-        if not material_group:
+        if not results:
             Logger.log("i", "Unable to duplicate the material with id %s, because it doesn't exist.", root_material_id)
             return None
 
-        base_container = material_group.root_material_node.container
-        if not base_container:
-            return None
+        base_container = results[0]
 
         # Ensure all settings are saved.
         cura.CuraApplication.CuraApplication.getInstance().saveSettings()
@@ -353,11 +299,9 @@ class MaterialManager(QObject):
         new_containers.append(new_base_container)
 
         # Clone all of them.
-        for node in material_group.derived_material_node_list:
-            container_to_copy = node.container
-            if not container_to_copy:
-                continue
-            # Create unique IDs for every clone.
+        for container_to_copy in container_registry.findContainers(base_file=root_material_id):
+            if container_to_copy.getId() == root_material_id:
+                continue  # We already have that one, skip it
             new_id = new_base_id
             if container_to_copy.getMetaDataEntry("definition") != "fdmprinter":
                 new_id += "_" + container_to_copy.getMetaDataEntry("definition")
@@ -371,7 +315,6 @@ class MaterialManager(QObject):
             if new_metadata is not None:
                 for key, value in new_metadata.items():
                     new_container.getMetaData()[key] = value
-
             new_containers.append(new_container)
 
         for container_to_add in new_containers:
@@ -383,8 +326,15 @@ class MaterialManager(QObject):
             self.addFavorite(new_base_id)
 
         return new_base_id
-
     #
+    # Creates a duplicate of a material, which has the same GUID and base_file metadata.
+    # Returns the root material ID of the duplicated material if successful.
+    #
+    @pyqtSlot("QVariant", result = str)
+    def duplicateMaterial(self, material_node: MaterialNode, new_base_id: Optional[str] = None, new_metadata: Dict[str, Any] = None) -> Optional[str]:
+        root_material_id = cast(str, material_node.getMetaDataEntry("base_file", ""))
+        return self.duplicateMaterialByRootId(root_material_id, new_base_id, new_metadata)
+
     # Create a new material by cloning Generic PLA for the current material diameter and generate a new GUID.
     # Returns the ID of the newly created material.
     @pyqtSlot(result = str)
@@ -403,11 +353,6 @@ class MaterialManager(QObject):
 
         approximate_diameter = str(extruder_stack.approximateMaterialDiameter)
         root_material_id = self.getRootMaterialIDForDiameter(root_material_id, approximate_diameter)
-        material_group = self.getMaterialGroup(root_material_id)
-
-        if not material_group:  # This should never happen
-            Logger.log("w", "Cannot get the material group of %s.", root_material_id)
-            return ""
 
         # Create a new ID & container to hold the data.
         new_id = CuraContainerRegistry.getInstance().uniqueName("custom_material")
@@ -416,9 +361,7 @@ class MaterialManager(QObject):
                         "GUID": str(uuid.uuid4()),
                         }
 
-        self.duplicateMaterial(material_group.root_material_node,
-                               new_base_id = new_id,
-                               new_metadata = new_metadata)
+        self.duplicateMaterialByRootId(root_material_id, new_base_id = new_id, new_metadata = new_metadata)
         return new_id
 
     @pyqtSlot(str)
diff --git a/cura/Machines/MaterialNode.py b/cura/Machines/MaterialNode.py
index 5fa28de77f..9421448287 100644
--- a/cura/Machines/MaterialNode.py
+++ b/cura/Machines/MaterialNode.py
@@ -1,7 +1,7 @@
 # Copyright (c) 2019 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
 
-from typing import TYPE_CHECKING
+from typing import Any, TYPE_CHECKING
 
 from UM.Settings.ContainerRegistry import ContainerRegistry
 from UM.Settings.Interfaces import ContainerInterface
@@ -23,8 +23,11 @@ class MaterialNode(ContainerNode):
         container_registry = ContainerRegistry.getInstance()
         my_metadata = container_registry.findContainersMetadata(id = container_id)[0]
         self.base_file = my_metadata["base_file"]
-        container_registry.containerAdded.connect(self._qualityAdded)
+        self.material_type = my_metadata["material"]
+        self.guid = my_metadata["GUID"]
         self._loadAll()
+        container_registry.containerRemoved.connect(self._onRemoved)
+        container_registry.containerMetaDataChanged.connect(self._onMetadataChanged)
 
     def _loadAll(self) -> None:
         container_registry = ContainerRegistry.getInstance()
@@ -33,14 +36,13 @@ class MaterialNode(ContainerNode):
             qualities = container_registry.findInstanceContainersMetadata(type = "quality", definition = "fdmprinter")
         else:
             # Need to find the qualities that specify a material profile with the same material type.
-            my_metadata = container_registry.findInstanceContainersMetadata(id = self.container_id)[0]
-            my_material_type = my_metadata.get("material")
+            my_material_type = self.material_type
             qualities = []
             qualities_any_material = container_registry.findInstanceContainersMetadata(type = "quality", definition = self.variant.machine.quality_definition, variant = self.variant.variant_name)
             for material_metadata in container_registry.findInstanceContainersMetadata(type = "material", material = my_material_type):
                 qualities.extend((quality for quality in qualities_any_material if quality["material"] == material_metadata["id"]))
             if not qualities:  # No quality profiles found. Go by GUID then.
-                my_guid = my_metadata.get("material")
+                my_guid = self.guid
                 for material_metadata in container_registry.findInstanceContainersMetadata(type = "material", guid = my_guid):
                     qualities.extend((quality for quality in qualities_any_material if quality["material"] == material_metadata["id"]))
 
@@ -49,37 +51,37 @@ class MaterialNode(ContainerNode):
             if quality_id not in self.qualities:
                 self.qualities[quality_id] = QualityNode(quality_id, parent = self)
 
-    def _qualityAdded(self, container: ContainerInterface) -> None:
-        if container.getMetaDataEntry("type") != "quality":
-            return  # Not interested.
-        if not self.variant.machine.has_machine_quality:
-            if container.getMetaDataEntry("definition") != "fdmprinter":
-                return  # Only want global qualities.
-        else:
-            if container.getMetaDataEntry("definition") != self.variant.machine.quality_definition:
-                return  # Doesn't match the machine.
-            if container.getMetaDataEntry("variant") != self.variant.variant_name:
-                return  # Doesn't match the variant.
-            # Detect if we're falling back to matching via GUID.
-            # If so, we might need to erase the current list and put just this one in (i.e. no longer use the fallback).
-            container_registry = ContainerRegistry.getInstance()
-            my_metadata = container_registry.findInstanceContainersMetadata(id = self.container_id)[0]
-            my_material_type = my_metadata.get("material")
-            allowed_material_ids = {metadata["id"] for metadata in container_registry.findInstanceContainersMetadata(type = "material", material = my_material_type)}
-            # Select any quality profile; if the material is not matching by material type, we've been falling back to GUID all along.
-            is_fallback_guid = len(self.qualities) == 0 or next(iter(self.qualities.values())).getMetaDataEntry("material") not in allowed_material_ids
+    ##  Triggered when any container is removed, but only handles it when the
+    #   container is removed that this node represents.
+    #   \param container The container that was allegedly removed.
+    def _onRemoved(self, container: ContainerInterface) -> None:
+        if container.getId() == self.container_id:
+            # Remove myself from my parent.
+            if self.base_file in self.variant.materials:
+                del self.variant.materials[self.base_file]
 
-            if is_fallback_guid and container.getMetaDataEntry("material") in allowed_material_ids:  # So far we needed the fallback, but no longer!
-                self.qualities.clear()  # It'll get filled with the new quality profile then.
-            else:
-                if not is_fallback_guid:
-                    if container.getMetaDataEntry("material") not in allowed_material_ids:
-                        return  # Doesn't match the material type.
-                else:
-                    my_material_guid = my_metadata.get("GUID")
-                    allowed_material_ids = {metadata["id"] for metadata in container_registry.findInstanceContainersMetadata(type = "material", guid = my_material_guid)}
-                    if container.getMetaDataEntry("material") not in allowed_material_ids:
-                        return  # Doesn't match the material GUID.
+    ##  Triggered when any metadata changed in any container, but only handles
+    #   it when the metadata of this node is changed.
+    #   \param container The container whose metadata changed.
+    #   \param kwargs Key-word arguments provided when changing the metadata.
+    #   These are ignored. As far as I know they are never provided to this
+    #   call.
+    def _onMetadataChanged(self, container: ContainerInterface, **kwargs: Any) -> None:
+        if container.getId() != self.container_id:
+            return
 
-        quality_id = container.getId()
-        self.qualities[quality_id] = QualityNode(quality_id, parent = self)
\ No newline at end of file
+        new_metadata = container.getMetaData()
+        old_base_file = self.base_file
+        if new_metadata["base_file"] != old_base_file:
+            self.base_file = new_metadata["base_file"]
+            if old_base_file in self.variant.materials:  # Move in parent node.
+                del self.variant.materials[old_base_file]
+            self.variant.materials[self.base_file] = self
+
+        old_material_type = self.material_type
+        self.material_type = new_metadata["material"]
+        old_guid = self.guid
+        self.guid = new_metadata["GUID"]
+        if self.base_file != old_base_file or self.material_type != old_material_type or self.guid != old_guid:  # List of quality profiles could've changed.
+            self.qualities = {}
+            self._loadAll()  # Re-load the quality profiles for this node.
\ No newline at end of file
diff --git a/cura/Machines/Models/BaseMaterialsModel.py b/cura/Machines/Models/BaseMaterialsModel.py
index cd8fc70dbd..188ce1791b 100644
--- a/cura/Machines/Models/BaseMaterialsModel.py
+++ b/cura/Machines/Models/BaseMaterialsModel.py
@@ -34,9 +34,6 @@ class BaseMaterialsModel(ListModel):
 
         # Update this model when switching machines
         self._machine_manager.activeStackChanged.connect(self._update)
-        
-        # Update this model when list of materials changes
-        self._material_manager.materialsUpdated.connect(self._update)
 
         self.addRoleName(Qt.UserRole + 1, "root_material_id")
         self.addRoleName(Qt.UserRole + 2, "id")
@@ -109,26 +106,24 @@ class BaseMaterialsModel(ListModel):
     #  so it's placed here for easy access.
     def _canUpdate(self):
         global_stack = self._machine_manager.activeMachine
-
         if global_stack is None or not self._enabled:
             return False
 
         extruder_position = str(self._extruder_position)
-
         if extruder_position not in global_stack.extruders:
             return False
-        
         extruder_stack = global_stack.extruders[extruder_position]
-        self._available_materials = self._material_manager.getAvailableMaterialsForMachineExtruder(global_stack, extruder_stack)
-        if self._available_materials is None:
-            return False
 
+        self._available_materials = self._material_manager.getAvailableMaterialsForMachineExtruder(global_stack, extruder_stack)
         return True
 
     ## This is another convenience function which is shared by all material
     #  models so it's put here to avoid having so much duplicated code.
     def _createMaterialItem(self, root_material_id, container_node):
-        metadata = CuraContainerRegistry.getInstance().findContainersMetadata(id = container_node.container_id)[0]
+        metadata_list = CuraContainerRegistry.getInstance().findContainersMetadata(id = container_node.container_id)
+        if not metadata_list:
+            return None
+        metadata = metadata_list[0]
         item = {
             "root_material_id":     root_material_id,
             "id":                   metadata["id"],
diff --git a/cura/Machines/Models/FavoriteMaterialsModel.py b/cura/Machines/Models/FavoriteMaterialsModel.py
index dda06a953a..bab0809ee0 100644
--- a/cura/Machines/Models/FavoriteMaterialsModel.py
+++ b/cura/Machines/Models/FavoriteMaterialsModel.py
@@ -2,11 +2,20 @@
 # Cura is released under the terms of the LGPLv3 or higher.
 
 from cura.Machines.Models.BaseMaterialsModel import BaseMaterialsModel
+import cura.CuraApplication  # To listen to changes to the preferences.
 
 ##  Model that shows the list of favorite materials.
 class FavoriteMaterialsModel(BaseMaterialsModel):
     def __init__(self, parent = None):
         super().__init__(parent)
+        cura.CuraApplication.CuraApplication.getInstance().getPreferences().preferenceChanged.connect(self._onFavoritesChanged)
+        self._update()
+
+    ##  Triggered when any preference changes, but only handles it when the list
+    #   of favourites is changed.
+    def _onFavoritesChanged(self, preference_key: str) -> None:
+        if preference_key != "cura/favorite_materials":
+            return
         self._update()
 
     def _update(self):
@@ -28,7 +37,8 @@ class FavoriteMaterialsModel(BaseMaterialsModel):
                 continue
 
             item = self._createMaterialItem(root_material_id, container_node)
-            item_list.append(item)
+            if item:
+                item_list.append(item)
 
         # Sort the item list alphabetically by name
         item_list = sorted(item_list, key = lambda d: d["brand"].upper())
diff --git a/cura/Machines/Models/GenericMaterialsModel.py b/cura/Machines/Models/GenericMaterialsModel.py
index 8a03dcfdeb..78d3641652 100644
--- a/cura/Machines/Models/GenericMaterialsModel.py
+++ b/cura/Machines/Models/GenericMaterialsModel.py
@@ -24,11 +24,12 @@ class GenericMaterialsModel(BaseMaterialsModel):
                 continue
 
             # Only add results for generic materials
-            if container_node.getMetaDataEntry("brand").lower() != "generic":
+            if container_node.getMetaDataEntry("brand", "unknown").lower() != "generic":
                 continue
 
             item = self._createMaterialItem(root_material_id, container_node)
-            item_list.append(item)
+            if item:
+                item_list.append(item)
 
         # Sort the item list alphabetically by name
         item_list = sorted(item_list, key = lambda d: d["name"].upper())
diff --git a/cura/Machines/Models/IntentModel.py b/cura/Machines/Models/IntentModel.py
index 275087689b..5a44883b76 100644
--- a/cura/Machines/Models/IntentModel.py
+++ b/cura/Machines/Models/IntentModel.py
@@ -8,6 +8,7 @@ from PyQt5.QtCore import Qt, QObject, pyqtProperty, pyqtSignal
 from UM.Qt.ListModel import ListModel
 from UM.Settings.ContainerRegistry import ContainerRegistry
 
+from cura.Machines.ContainerTree import ContainerTree
 from cura.Settings.IntentManager import IntentManager
 import cura.CuraApplication
 
@@ -47,13 +48,11 @@ class IntentModel(ListModel):
 
     def _update(self) -> None:
         new_items = []  # type: List[Dict[str, Any]]
-        application = cura.CuraApplication.CuraApplication.getInstance()
-        quality_manager = application.getQualityManager()
-        global_stack = application.getGlobalContainerStack()
+        global_stack = cura.CuraApplication.CuraApplication.getInstance().getGlobalContainerStack()
         if not global_stack:
             self.setItems(new_items)
             return
-        quality_groups = quality_manager.getQualityGroups(global_stack)
+        quality_groups = ContainerTree.getInstance().getCurrentQualityGroups()
 
         for intent_category, quality_type in IntentManager.getInstance().getCurrentAvailableIntents():
             if intent_category == self._intent_category:
diff --git a/cura/Machines/Models/MaterialBrandsModel.py b/cura/Machines/Models/MaterialBrandsModel.py
index c4721db5f7..85167632af 100644
--- a/cura/Machines/Models/MaterialBrandsModel.py
+++ b/cura/Machines/Models/MaterialBrandsModel.py
@@ -55,7 +55,8 @@ class MaterialBrandsModel(BaseMaterialsModel):
 
             # Now handle the individual materials
             item = self._createMaterialItem(root_material_id, container_node)
-            brand_group_dict[brand][material_type].append(item)
+            if item:
+                brand_group_dict[brand][material_type].append(item)
 
         # Part 2: Organize the tree into models
         #
diff --git a/cura/Machines/Models/QualityManagementModel.py b/cura/Machines/Models/QualityManagementModel.py
index 315ab010bb..2a661ec49e 100644
--- a/cura/Machines/Models/QualityManagementModel.py
+++ b/cura/Machines/Models/QualityManagementModel.py
@@ -1,10 +1,11 @@
-# Copyright (c) 2018 Ultimaker B.V.
+# Copyright (c) 2019 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
 
 from PyQt5.QtCore import Qt, pyqtSlot
 
-from UM.Qt.ListModel import ListModel
 from UM.Logger import Logger
+from UM.Qt.ListModel import ListModel
+from cura.Machines.ContainerTree import ContainerTree
 
 #
 # This the QML model for the quality management page.
@@ -42,7 +43,7 @@ class QualityManagementModel(ListModel):
             self.setItems([])
             return
 
-        quality_group_dict = self._quality_manager.getQualityGroups(global_stack)
+        quality_group_dict = ContainerTree.getInstance().getCurrentQualityGroups()
         quality_changes_group_dict = self._quality_manager.getQualityChangesGroups(global_stack)
 
         available_quality_types = set(quality_type for quality_type, quality_group in quality_group_dict.items()
diff --git a/cura/Machines/QualityManager.py b/cura/Machines/QualityManager.py
index 07ef857af4..57bcaa9c70 100644
--- a/cura/Machines/QualityManager.py
+++ b/cura/Machines/QualityManager.py
@@ -105,37 +105,12 @@ class QualityManager(QObject):
     #   \return A dictionary with quality types as keys and the quality groups
     #   for those types as values.
     def getQualityGroups(self, global_stack: "GlobalStack") -> Dict[str, QualityGroup]:
+        # Gather up the variant names and material base files for each extruder.
+        variant_names = [extruder.variant.getName() for extruder in global_stack.extruders.values()]
+        material_bases = [extruder.material.getMetaDataEntry("base_file") for extruder in global_stack.extruders.values()]
+        extruder_enabled = [extruder.isEnabled for extruder in global_stack.extruders.values()]
         definition_id = global_stack.definition.getId()
-        machine_node = ContainerTree.getInstance().machines[definition_id]
-
-        # For each extruder, find which quality profiles are available. Later we'll intersect the quality types.
-        qualities_per_type_per_extruder = {}  # type: Dict[str, Dict[str, QualityNode]]
-        for extruder_nr, extruder in global_stack.extruders.items():
-            if not extruder.isEnabled:
-                continue # No qualities available in this extruder. It'll get skipped when intersecting the quality types.
-            nozzle_name = extruder.variant.getName()
-            material_base = extruder.material.getMetaDataEntry("base_file")
-            if nozzle_name not in machine_node.variants or material_base not in machine_node.variants[nozzle_name].materials:
-                # The printer has no variant/material-specific quality profiles. Use the global quality profiles.
-                qualities_per_type_per_extruder[extruder_nr] = machine_node.global_qualities
-            else:
-                # Use the actually specialised quality profiles.
-                qualities_per_type_per_extruder[extruder_nr] = machine_node.variants[nozzle_name].materials[material_base].qualities
-
-        # Create the quality group for each available type.
-        quality_groups = {}
-        for quality_type, global_quality_node in machine_node.global_qualities.items():
-            quality_groups[quality_type] = QualityGroup(name = global_quality_node.getMetaDataEntry("name", "Unnamed profile"), quality_type = quality_type)
-            quality_groups[quality_type].node_for_global = global_quality_node
-            for extruder, qualities_per_type in qualities_per_type_per_extruder:
-                quality_groups[quality_type].nodes_for_extruders[extruder] = qualities_per_type[quality_type]
-
-        available_quality_types = set(quality_groups.keys())
-        for qualities_per_type in qualities_per_type_per_extruder.values():
-            available_quality_types.intersection_update(qualities_per_type.keys())
-        for quality_type in available_quality_types:
-            quality_groups[quality_type].is_available = True
-        return quality_groups
+        return ContainerTree.getInstance().machines[definition_id].getQualityGroups(variant_names, material_bases, extruder_enabled)
 
     def getQualityGroupsForMachineDefinition(self, machine: "GlobalStack") -> Dict[str, QualityGroup]:
         machine_definition_id = getMachineDefinitionIDForQualitySearch(machine.definition)
@@ -160,11 +135,22 @@ class QualityManager(QObject):
 
         return quality_group_dict
 
+    ##  Get the quality group for the preferred quality type for a certain
+    #   global stack.
+    #
+    #   If the preferred quality type is not available, ``None`` will be
+    #   returned.
+    #   \param machine The global stack of the machine to get the preferred
+    #   quality group for.
+    #   \return The preferred quality group, or ``None`` if that is not
+    #   available.
     def getDefaultQualityType(self, machine: "GlobalStack") -> Optional[QualityGroup]:
-        preferred_quality_type = machine.definition.getMetaDataEntry("preferred_quality_type")
-        quality_group_dict = self.getQualityGroups(machine)
-        quality_group = quality_group_dict.get(preferred_quality_type)
-        return quality_group
+        machine_node = ContainerTree.getInstance().machines[machine.definition.getId()]
+        quality_groups = self.getQualityGroups(machine)
+        result = quality_groups.get(machine_node.preferred_quality_type)
+        if result is not None and result.is_available:
+            return result
+        return None  # If preferred quality type is not available, leave it up for the caller.
 
 
     #
diff --git a/cura/Machines/QualityNode.py b/cura/Machines/QualityNode.py
index 8e58700589..09785056f1 100644
--- a/cura/Machines/QualityNode.py
+++ b/cura/Machines/QualityNode.py
@@ -4,7 +4,6 @@
 from typing import Union, TYPE_CHECKING
 
 from UM.Settings.ContainerRegistry import ContainerRegistry
-from UM.Settings.Interfaces import ContainerInterface
 from cura.Machines.ContainerNode import ContainerNode
 from cura.Machines.IntentNode import IntentNode
 
@@ -21,7 +20,6 @@ class QualityNode(ContainerNode):
         super().__init__(container_id)
         self.parent = parent
         self.intents = {}  # type: Dict[str, IntentNode]
-        ContainerRegistry.getInstance().containerAdded.connect(self._intentAdded)
         self._loadAll()
 
     def _loadAll(self) -> None:
@@ -31,21 +29,4 @@ class QualityNode(ContainerNode):
         if not isinstance(self.parent, MachineNode):  # Not a global profile.
             for intent in container_registry.findInstanceContainersMetadata(type = "intent", definition = self.parent.variant.machine.quality_definition, variant = self.parent.variant.variant_name, material = self.parent.base_file):
                 self.intents[intent["id"]] = IntentNode(intent["id"], quality = self)
-        # Otherwise, there are no intents for global profiles.
-
-    def _intentAdded(self, container: ContainerInterface) -> None:
-        from cura.Machines.MachineNode import MachineNode  # Imported here to prevent circular imports.
-        if container.getMetaDataEntry("type") != "intent":
-            return  # Not interested if it's not an intent.
-        if isinstance(self.parent, MachineNode):
-            return  # Global profiles don't have intents.
-        if container.getMetaDataEntry("definition") != self.parent.variant.machine.quality_definition:
-            return  # Incorrect printer.
-        if container.getMetaDataEntry("variant") != self.parent.variant.variant_name:
-            return  # Incorrect variant.
-        if container.getMetaDataEntry("material") != self.parent.base_file:
-            return  # Incorrect material.
-        container_id = container.getId()
-        if container_id in self.intents:
-            return  # Already have this.
-        self.intents[container_id] = IntentNode(container_id, quality = self)
\ No newline at end of file
+        # Otherwise, there are no intents for global profiles.
\ No newline at end of file
diff --git a/cura/Machines/VariantManager.py b/cura/Machines/VariantManager.py
index c80545145f..9c074dcf17 100644
--- a/cura/Machines/VariantManager.py
+++ b/cura/Machines/VariantManager.py
@@ -115,7 +115,7 @@ class VariantManager:
                        variant_type: Optional["VariantType"] = None) -> Optional["ContainerNode"]:
         if variant_type is None:
             variant_node = None
-            variant_type_dict = self._machine_to_variant_dict_map[machine_definition_id]
+            variant_type_dict = self._machine_to_variant_dict_map.get("machine_definition_id", {})
             for variant_dict in variant_type_dict.values():
                 if variant_name in variant_dict:
                     variant_node = variant_dict[variant_name]
diff --git a/cura/Settings/ContainerManager.py b/cura/Settings/ContainerManager.py
index 1438faee96..4edddb9d83 100644
--- a/cura/Settings/ContainerManager.py
+++ b/cura/Settings/ContainerManager.py
@@ -9,7 +9,6 @@ from typing import Dict, Union, Any, TYPE_CHECKING, List
 from PyQt5.QtCore import QObject, QUrl
 from PyQt5.QtWidgets import QMessageBox
 
-
 from UM.i18n import i18nCatalog
 from UM.FlameProfiler import pyqtSlot
 from UM.Logger import Logger
@@ -17,18 +16,19 @@ from UM.MimeTypeDatabase import MimeTypeDatabase, MimeTypeNotFoundError
 from UM.Platform import Platform
 from UM.SaveFile import SaveFile
 from UM.Settings.ContainerFormatError import ContainerFormatError
+from UM.Settings.ContainerRegistry import ContainerRegistry
 from UM.Settings.ContainerStack import ContainerStack
 from UM.Settings.DefinitionContainer import DefinitionContainer
 from UM.Settings.InstanceContainer import InstanceContainer
 import cura.CuraApplication
-
+from cura.Machines.MaterialManager import MaterialManager
 
 if TYPE_CHECKING:
     from cura.CuraApplication import CuraApplication
     from cura.Machines.ContainerNode import ContainerNode
     from cura.Machines.MaterialNode import MaterialNode
     from cura.Machines.QualityChangesGroup import QualityChangesGroup
-    from cura.Machines.MaterialManager import MaterialManager
+
     from cura.Machines.QualityManager import QualityManager
 
 catalog = i18nCatalog("cura")
@@ -323,22 +323,18 @@ class ContainerManager(QObject):
 
     ##  Get a list of materials that have the same GUID as the reference material
     #
-    #   \param material_id \type{str} the id of the material for which to get the linked materials.
-    #   \return \type{list} a list of names of materials with the same GUID
+    #   \param material_node The node representing the material for which to get
+    #   the same GUID.
+    #   \param exclude_self Whether to include the name of the material you
+    #   provided.
+    #   \return A list of names of materials with the same GUID.
     @pyqtSlot("QVariant", bool, result = "QStringList")
-    def getLinkedMaterials(self, material_node: "MaterialNode", exclude_self: bool = False):
-        guid = material_node.getMetaDataEntry("GUID", "")
-
-        self_root_material_id = material_node.getMetaDataEntry("base_file")
-        material_group_list = MaterialManager.getInstance().getMaterialGroupListByGUID(guid)
-
-        linked_material_names = []
-        if material_group_list:
-            for material_group in material_group_list:
-                if exclude_self and material_group.name == self_root_material_id:
-                    continue
-                linked_material_names.append(material_group.root_material_node.getMetaDataEntry("name", ""))
-        return linked_material_names
+    def getLinkedMaterials(self, material_node: "MaterialNode", exclude_self: bool = False) -> List[str]:
+        same_guid = ContainerRegistry.getInstance().findInstanceContainersMetadata(guid = material_node.guid)
+        if exclude_self:
+            return [metadata["name"] for metadata in same_guid if metadata["base_file"] != material_node.base_file]
+        else:
+            return [metadata["name"] for metadata in same_guid]
 
     ##  Unlink a material from all other materials by creating a new GUID
     #   \param material_id \type{str} the id of the material to create a new GUID for.
diff --git a/cura/Settings/CuraStackBuilder.py b/cura/Settings/CuraStackBuilder.py
index e5bce516bf..d0424983cd 100644
--- a/cura/Settings/CuraStackBuilder.py
+++ b/cura/Settings/CuraStackBuilder.py
@@ -28,7 +28,6 @@ class CuraStackBuilder:
     def createMachine(cls, name: str, definition_id: str) -> Optional[GlobalStack]:
         from cura.CuraApplication import CuraApplication
         application = CuraApplication.getInstance()
-        quality_manager = application.getQualityManager()
         registry = application.getContainerRegistry()
 
         definitions = registry.findDefinitionContainers(id = definition_id)
@@ -64,7 +63,7 @@ class CuraStackBuilder:
             registry.addContainer(new_extruder)
 
         preferred_quality_type = machine_definition.getMetaDataEntry("preferred_quality_type")
-        quality_group_dict = quality_manager.getQualityGroups(new_global_stack)
+        quality_group_dict = ContainerTree.getInstance().getCurrentQualityGroups()
         if not quality_group_dict:
             # There is no available quality group, set all quality containers to empty.
             new_global_stack.quality = application.empty_quality_container
diff --git a/cura/Settings/IntentManager.py b/cura/Settings/IntentManager.py
index 5a3c1a737f..2cfbf11ae2 100644
--- a/cura/Settings/IntentManager.py
+++ b/cura/Settings/IntentManager.py
@@ -4,6 +4,7 @@
 from PyQt5.QtCore import QObject, pyqtProperty, pyqtSignal, pyqtSlot
 from typing import Any, Dict, List, Optional, Set, Tuple, TYPE_CHECKING
 import cura.CuraApplication
+from cura.Machines.ContainerTree import ContainerTree
 from cura.Settings.cura_empty_instance_containers import empty_intent_container
 from UM.Settings.InstanceContainer import InstanceContainer
 
@@ -75,7 +76,8 @@ class IntentManager(QObject):
             # TODO: We now do this (return a default) if the global stack is missing, but not in the code below,
             #       even though there should always be defaults. The problem then is what to do with the quality_types.
             #       Currently _also_ inconsistent with 'currentAvailableIntentCategories', which _does_ return default.
-        quality_groups = application.getQualityManager().getQualityGroups(global_stack)
+        quality_groups = ContainerTree.getInstance().getCurrentQualityGroups()
+        # TODO: These quality nodes in that tree already contain the intent nodes. We can optimise this.
         available_quality_types = {quality_group.quality_type for quality_group in quality_groups.values() if quality_group.node_for_global is not None}
 
         final_intent_ids = set()  # type: Set[str]
diff --git a/plugins/UM3NetworkPrinting/src/Models/Http/ClusterPrinterConfigurationMaterial.py b/plugins/UM3NetworkPrinting/src/Models/Http/ClusterPrinterConfigurationMaterial.py
index aea244b31d..8edb9fb808 100644
--- a/plugins/UM3NetworkPrinting/src/Models/Http/ClusterPrinterConfigurationMaterial.py
+++ b/plugins/UM3NetworkPrinting/src/Models/Http/ClusterPrinterConfigurationMaterial.py
@@ -1,8 +1,9 @@
 # Copyright (c) 2019 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
+
 from typing import Optional
 
-from cura.CuraApplication import CuraApplication
+from UM.Settings.ContainerRegistry import ContainerRegistry
 from cura.PrinterOutput.Models.MaterialOutputModel import MaterialOutputModel
 
 from ..BaseModel import BaseModel
@@ -24,32 +25,27 @@ class ClusterPrinterConfigurationMaterial(BaseModel):
         self.material = material
         super().__init__(**kwargs)
 
-    ## Creates a material output model based on this cloud printer material.
+    ##  Creates a material output model based on this cloud printer material.
+    #
+    #   A material is chosen that matches the current GUID. If multiple such
+    #   materials are available, read-only materials are preferred and the
+    #   material with the earliest alphabetical name will be selected.
+    #   \return A material output model that matches the current GUID.
     def createOutputModel(self) -> MaterialOutputModel:
-        material_manager = CuraApplication.getInstance().getMaterialManager()
-        material_group_list = material_manager.getMaterialGroupListByGUID(self.guid) or []
-
-        # Sort the material groups by "is_read_only = True" first, and then the name alphabetically.
-        read_only_material_group_list = list(filter(lambda x: x.is_read_only, material_group_list))
-        non_read_only_material_group_list = list(filter(lambda x: not x.is_read_only, material_group_list))
-        material_group = None
-        if read_only_material_group_list:
-            read_only_material_group_list = sorted(read_only_material_group_list, key = lambda x: x.name)
-            material_group = read_only_material_group_list[0]
-        elif non_read_only_material_group_list:
-            non_read_only_material_group_list = sorted(non_read_only_material_group_list, key = lambda x: x.name)
-            material_group = non_read_only_material_group_list[0]
-
-        if material_group:
-            container = material_group.root_material_node.container
-            color = container.getMetaDataEntry("color_code")
-            brand = container.getMetaDataEntry("brand")
-            material_type = container.getMetaDataEntry("material")
-            name = container.getName()
+        container_registry = ContainerRegistry.getInstance()
+        same_guid = container_registry.findInstanceContainersMetadata(GUID = self.guid)
+        if same_guid:
+            read_only = sorted(filter(lambda metadata: container_registry.isReadOnly(metadata["id"]), same_guid), key = lambda metadata: metadata["name"])
+            if read_only:
+                material_metadata = read_only[0]
+            else:
+                material_metadata = min(same_guid, key = lambda metadata: metadata["name"])
         else:
-            color = self.color
-            brand = self.brand
-            material_type = self.material
-            name = "Empty" if self.material == "empty" else "Unknown"
+            material_metadata = {
+                "color_code": self.color,
+                "brand": self.brand,
+                "material": self.material,
+                "name": "Empty" if self.material == "empty" else "Unknown"
+            }
 
-        return MaterialOutputModel(guid=self.guid, type=material_type, brand=brand, color=color, name=name)
+        return MaterialOutputModel(guid = self.guid, type = material_metadata["material"], brand = material_metadata["brand"], color = material_metadata["color_code"], name = material_metadata["name"])
diff --git a/plugins/XmlMaterialProfile/XmlMaterialProfile.py b/plugins/XmlMaterialProfile/XmlMaterialProfile.py
index 2ab9e701eb..157d871d54 100644
--- a/plugins/XmlMaterialProfile/XmlMaterialProfile.py
+++ b/plugins/XmlMaterialProfile/XmlMaterialProfile.py
@@ -244,7 +244,10 @@ class XmlMaterialProfile(InstanceContainer):
 
             variant_name = container.getMetaDataEntry("variant_name")
             if variant_name:
-                variant_dict = {"variant_node": variant_manager.getVariantNode(definition_id, variant_name),
+                variant_node = variant_manager.getVariantNode(definition_id, variant_name)
+                if variant_node is None:
+                    continue
+                variant_dict = {"variant_node":variant_node ,
                                 "material_container": container}
                 machine_variant_map[definition_id][variant_name] = variant_dict
                 continue
diff --git a/resources/qml/Preferences/Materials/MaterialsPage.qml b/resources/qml/Preferences/Materials/MaterialsPage.qml
index a0ce3c4b49..481a256501 100644
--- a/resources/qml/Preferences/Materials/MaterialsPage.qml
+++ b/resources/qml/Preferences/Materials/MaterialsPage.qml
@@ -17,6 +17,8 @@ Item
     property var resetEnabled: false
     property var currentItem: null
 
+    property var materialManager: CuraApplication.getMaterialManager()
+
     property var hasCurrentItem: base.currentItem != null
     property var isCurrentItemActivated:
     {
@@ -119,7 +121,7 @@ Item
             onClicked:
             {
                 forceActiveFocus();
-                base.newRootMaterialIdToSwitchTo = CuraApplication.getMaterialManager().createMaterial();
+                base.newRootMaterialIdToSwitchTo = base.materialManager.createMaterial();
                 base.toActivateNewMaterial = true;
             }
         }
@@ -134,7 +136,7 @@ Item
             onClicked:
             {
                 forceActiveFocus();
-                base.newRootMaterialIdToSwitchTo = CuraApplication.getMaterialManager().duplicateMaterial(base.currentItem.container_node);
+                base.newRootMaterialIdToSwitchTo = base.materialManager.duplicateMaterial(base.currentItem.container_node);
                 base.toActivateNewMaterial = true;
             }
         }
@@ -145,7 +147,8 @@ Item
             id: removeMenuButton
             text: catalog.i18nc("@action:button", "Remove")
             iconName: "list-remove"
-            enabled: base.hasCurrentItem && !base.currentItem.is_read_only && !base.isCurrentItemActivated && CuraApplication.getMaterialManager().canMaterialBeRemoved(base.currentItem.container_node)
+            enabled: base.hasCurrentItem && !base.currentItem.is_read_only && !base.isCurrentItemActivated && base.materialManager.canMaterialBeRemoved(base.currentItem.container_node)
+
             onClicked:
             {
                 forceActiveFocus();
@@ -294,7 +297,7 @@ Item
         {
             // Set the active material as the fallback. It will be selected when the current material is deleted
             base.newRootMaterialIdToSwitchTo = base.active_root_material_id
-            CuraApplication.getMaterialManager().removeMaterial(base.currentItem.container_node);
+            base.materialManager.removeMaterial(base.currentItem.container_node);
         }
     }
 
diff --git a/tests/Machines/TestMachineNode.py b/tests/Machines/TestMachineNode.py
index db3946fc3a..fe0330609a 100644
--- a/tests/Machines/TestMachineNode.py
+++ b/tests/Machines/TestMachineNode.py
@@ -4,14 +4,6 @@ import pytest
 from UM.Settings.Interfaces import ContainerInterface
 from cura.Machines.MachineNode import MachineNode
 
-
-machine_node_variant_added_test_data = [({"type": "Not a variant!"}, ["Variant One", "Variant Two"]),  # Wrong type
-                                        ({"type": "variant", "name": "Variant One"}, ["Variant One", "Variant Two"]),  # Name already added
-                                        ({"type": "variant", "name": "Variant Three", "hardware_type": "Not a nozzle"}, ["Variant One", "Variant Two"]),  # Wrong hardware type
-                                        ({"type": "variant", "name": "Variant Three", "hardware_type": "nozzle", "definition": "machine_3"}, ["Variant One", "Variant Two"]),  # Wrong definition ID
-                                        ({"type": "variant", "name": "Variant Three", "hardware_type": "nozzle", "definition": "machine_1"}, ["Variant One", "Variant Two", "Variant Three"])] # Yay! It's finally added
-
-
 metadata_dict = {}
 
 
@@ -44,18 +36,4 @@ def test_machineNodeInit(container_registry):
     # As variants get stored by name, we want to check if those get added.
     assert "Variant One" in machine_node.variants
     assert "Variant Two" in machine_node.variants
-    assert len(machine_node.variants) == 2  # And ensure that *only* those two got added.
-
-
-@pytest.mark.parametrize("metadata,variant_result_list", machine_node_variant_added_test_data)
-def test_machineNodeVariantAdded(container_registry, metadata, variant_result_list):
-    machine_node = createMachineNode("machine_1", container_registry)
-
-    with patch("cura.Machines.MachineNode.VariantNode"):  # We're not testing the variant node here, so patch it out.
-        with patch.dict(metadata_dict, metadata):
-            mocked_container = createMockedInstanceContainer()
-            machine_node._variantAdded(mocked_container)
-
-    assert len(variant_result_list) == len(machine_node.variants)
-    for name in variant_result_list:
-        assert name in machine_node.variants
\ No newline at end of file
+    assert len(machine_node.variants) == 2  # And ensure that *only* those two got added.
\ No newline at end of file
diff --git a/tests/Machines/TestMaterialNode.py b/tests/Machines/TestMaterialNode.py
index 099be2b891..f9ea0e3622 100644
--- a/tests/Machines/TestMaterialNode.py
+++ b/tests/Machines/TestMaterialNode.py
@@ -6,21 +6,6 @@ from cura.Machines.MaterialNode import MaterialNode
 instance_container_metadata_dict = {"fdmprinter": {"no_variant": [{"id": "quality_1", "material": "material_1"}]},
                                     "machine_1": {"variant_1": {"material_1": [{"id": "quality_2", "material": "material_1"}, {"id": "quality_3","material": "material_1"}]}}}
 
-
-quality_metadata_machine_quality_test_data = [({"type": "Not a quality"}, ["quality_2", "quality_3"]),  # Wrong type
-                              ({"type": "quality", "definition": "machine_2"}, ["quality_2", "quality_3"]),  # Wrong defintion
-                              ({"type": "quality", "definition": "machine_1", "variant": "variant_2"}, ["quality_2", "quality_3"]), # Wrong variant
-                              ({"type": "quality", "definition": "machine_1", "variant": "variant_1", "material": "material_2"}, ["quality_2", "quality_3"]),  # wrong material
-
-                             ]
-
-quality_metadata_no_machine_quality =[({"type": "Not a quality"}, ["quality_1"]),  # Wrong type
-                                ({"type": "quality", "definition": "machine_1"}, ["quality_1"]),  # Wrong defintion (it needs fdmprinter)
-                              ({"type": "quality", "definition": "fdmprinter", "variant": "variant_2"}, ["quality_1", "quality_4"]), # Wrong variant, but should be added (as we ignore the variant)
-                              ({"type": "quality", "definition": "fdmprinter", "variant": "variant_1", "material": "material_2"}, ["quality_1", "quality_4"]),  # wrong material,  but should be added (as we ignore the material)
-                              ({"type": "quality", "definition": "fdmprinter", "variant": "variant_1", "material": "material_1"}, ["quality_1", "quality_4"]),
-                             ]
-
 metadata_dict = {}
 
 
@@ -86,45 +71,4 @@ def test_materialNodeInit_MachineQuality(container_registry):
 
     assert len(node.qualities) == 2
     assert "quality_2" in node.qualities
-    assert "quality_3" in node.qualities
-
-
-@pytest.mark.parametrize("metadata,qualities_result_list", quality_metadata_machine_quality_test_data)
-def test_qualityAdded_hasMachineQuality(container_registry, metadata, qualities_result_list):
-    variant_node = MagicMock()
-    variant_node.variant_name = "variant_1"
-    variant_node.machine.has_machine_quality = True
-    variant_node.machine.quality_definition = "machine_1"
-
-    container = createMockedInstanceContainer("quality_4")
-
-    with patch("cura.Machines.MaterialNode.QualityNode"):
-        with patch("UM.Settings.ContainerRegistry.ContainerRegistry.getInstance", MagicMock(return_value=container_registry)):
-            node = MaterialNode("material_1", variant_node)
-
-            with patch.dict(metadata_dict, metadata):
-                node._qualityAdded(container)
-
-    assert len(qualities_result_list) == len(node.qualities)
-    for name in qualities_result_list:
-        assert name in node.qualities
-
-
-@pytest.mark.parametrize("metadata,qualities_result_list", quality_metadata_no_machine_quality)
-def test_qualityAdded_noMachineQuality(container_registry, metadata, qualities_result_list):
-    variant_node = MagicMock()
-    variant_node.variant_name = "variant_1"
-    variant_node.machine.has_machine_quality = False
-
-    container = createMockedInstanceContainer("quality_4")
-
-    with patch("cura.Machines.MaterialNode.QualityNode"):
-        with patch("UM.Settings.ContainerRegistry.ContainerRegistry.getInstance", MagicMock(return_value=container_registry)):
-            node = MaterialNode("material_1", variant_node)
-
-            with patch.dict(metadata_dict, metadata):
-                node._qualityAdded(container)
-
-    assert len(qualities_result_list) == len(node.qualities)
-    for name in qualities_result_list:
-        assert name in node.qualities
\ No newline at end of file
+    assert "quality_3" in node.qualities
\ No newline at end of file
diff --git a/tests/Machines/TestQualityNode.py b/tests/Machines/TestQualityNode.py
index cad30d642c..64685689c2 100644
--- a/tests/Machines/TestQualityNode.py
+++ b/tests/Machines/TestQualityNode.py
@@ -1,21 +1,12 @@
 from unittest.mock import patch, MagicMock
 import pytest
 
-from cura.Machines.MaterialNode import MaterialNode
 from cura.Machines.QualityNode import QualityNode
 
 
 instance_container_metadata_dict = {"fdmprinter": {"variant_1": {"material_1": [{"id": "intent_1"}, {"id": "intent_2"}]}},
                                     "machine_1": {"variant_2": {"material_2": [{"id": "intent_3"}, {"id": "intent_4"}]}}}
 
-
-intent_metadata_intent_added_data = [({"type": "Not an intent"}, ["intent_3", "intent_4"]),  # Wrong type
-                                    ({"type": "intent", "definition": "machine_9000"}, ["intent_3", "intent_4"]),  # wrong definition
-                                    ({"type": "intent", "definition": "machine_1", "variant": "variant_299101"}, ["intent_3", "intent_4"]),  # wrong variant
-                                    ({"type": "intent", "definition": "machine_1", "variant": "variant_2", "material": "super cool material!"}, ["intent_3", "intent_4"]),  # Wrong material
-                                    ({"type": "intent", "definition": "machine_1", "variant": "variant_2", "material": "material_2"}, ["intent_3", "intent_4", "intent_9001"]),  # Yay, all good.
-]
-
 metadata_dict = {}
 
 
@@ -55,24 +46,4 @@ def test_qualityNode_machine_1(container_registry):
 
     assert len(node.intents) == 2
     assert "intent_3" in node.intents
-    assert "intent_4" in node.intents
-
-@pytest.mark.parametrize("metadata,intent_result_list", intent_metadata_intent_added_data)
-def test_intentNodeAdded(container_registry, metadata, intent_result_list):
-    material_node = MagicMock()
-    material_node.variant.machine.quality_definition = "machine_1"
-    material_node.variant.variant_name = "variant_2"
-    material_node.base_file = "material_2"
-
-    intent_container = createMockedInstanceContainer("intent_9001")
-
-    with patch("cura.Machines.QualityNode.IntentNode"):
-        with patch("UM.Settings.ContainerRegistry.ContainerRegistry.getInstance", MagicMock(return_value=container_registry)):
-            node = QualityNode("quality_1", material_node)
-            with patch.dict(metadata_dict, metadata):
-                node._intentAdded(intent_container)
-
-    assert len(intent_result_list) == len(node.intents)
-    for identifier in intent_result_list:
-        assert identifier in node.intents
-
+    assert "intent_4" in node.intents
\ No newline at end of file