diff --git a/cura/PrinterOutput/NetworkedPrinterOutputDevice.py b/cura/PrinterOutput/NetworkedPrinterOutputDevice.py
index 35d2ce014a..9a3be936a2 100644
--- a/cura/PrinterOutput/NetworkedPrinterOutputDevice.py
+++ b/cura/PrinterOutput/NetworkedPrinterOutputDevice.py
@@ -147,6 +147,9 @@ class NetworkedPrinterOutputDevice(PrinterOutputDevice):
         request.setHeader(QNetworkRequest.UserAgentHeader, self._user_agent)
         return request
 
+    def createFormPart(self, content_header: str, data: bytes, content_type: Optional[str] = None) -> QHttpPart:
+        return self._createFormPart(content_header, data, content_type)
+
     def _createFormPart(self, content_header: str, data: bytes, content_type: Optional[str] = None) -> QHttpPart:
         part = QHttpPart()
 
diff --git a/plugins/UM3NetworkPrinting/src/Models.py b/plugins/UM3NetworkPrinting/src/Models.py
new file mode 100644
index 0000000000..2bcac70766
--- /dev/null
+++ b/plugins/UM3NetworkPrinting/src/Models.py
@@ -0,0 +1,43 @@
+# Copyright (c) 2018 Ultimaker B.V.
+# Cura is released under the terms of the LGPLv3 or higher.
+
+
+## Base model that maps kwargs to instance attributes.
+class BaseModel:
+    def __init__(self, **kwargs) -> None:
+        self.__dict__.update(kwargs)
+        self.validate()
+
+    def validate(self) -> None:
+        pass
+
+
+##  Class representing a material that was fetched from the cluster API.
+class ClusterMaterial(BaseModel):
+    def __init__(self, guid: str, version: int, **kwargs) -> None:
+        self.guid = guid  # type: str
+        self.version = version  # type: int
+        super().__init__(**kwargs)
+
+    def validate(self) -> None:
+        if not self.guid:
+            raise ValueError("guid is required on ClusterMaterial")
+        if not self.version:
+            raise ValueError("version is required on ClusterMaterial")
+
+
+##  Class representing a local material that was fetched from the container registry.
+class LocalMaterial(BaseModel):
+    def __init__(self, GUID: str, id: str, version: int, **kwargs) -> None:
+        self.GUID = GUID  # type: str
+        self.id = id  # type: str
+        self.version = version  # type: int
+        super().__init__(**kwargs)
+
+    def validate(self) -> None:
+        if not self.GUID:
+            raise ValueError("guid is required on LocalMaterial")
+        if not self.version:
+            raise ValueError("version is required on LocalMaterial")
+        if not self.id:
+            raise ValueError("id is required on LocalMaterial")
diff --git a/plugins/UM3NetworkPrinting/src/SendMaterialJob.py b/plugins/UM3NetworkPrinting/src/SendMaterialJob.py
index 8491e79c29..f536fad49a 100644
--- a/plugins/UM3NetworkPrinting/src/SendMaterialJob.py
+++ b/plugins/UM3NetworkPrinting/src/SendMaterialJob.py
@@ -1,99 +1,197 @@
 # Copyright (c) 2018 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
+import json
+import os
+import urllib.parse
+from typing import Dict, TYPE_CHECKING, Set
 
-import json #To understand the list of materials from the printer reply.
-import os #To walk over material files.
-import os.path #To filter on material files.
-from PyQt5.QtNetwork import QNetworkReply, QNetworkRequest #To listen to the reply from the printer.
-from typing import Any, Dict, Set, TYPE_CHECKING
-import urllib.parse #For getting material IDs from their file names.
+from PyQt5.QtNetwork import QNetworkReply, QNetworkRequest
 
-from UM.Job import Job #The interface we're implementing.
+from UM.Application import Application
+from UM.Job import Job
 from UM.Logger import Logger
-from UM.MimeTypeDatabase import MimeTypeDatabase #To strip the extensions of the material profile files.
+from UM.MimeTypeDatabase import MimeTypeDatabase
 from UM.Resources import Resources
-from UM.Settings.ContainerRegistry import ContainerRegistry #To find the GUIDs of materials.
-
-from cura.CuraApplication import CuraApplication #For the resource types.
+from cura.CuraApplication import CuraApplication
+# Absolute imports don't work in plugins
+from .Models import ClusterMaterial, LocalMaterial
 
 if TYPE_CHECKING:
     from .ClusterUM3OutputDevice import ClusterUM3OutputDevice
 
+
 ##  Asynchronous job to send material profiles to the printer.
 #
 #   This way it won't freeze up the interface while sending those materials.
 class SendMaterialJob(Job):
+
     def __init__(self, device: "ClusterUM3OutputDevice") -> None:
         super().__init__()
-        self.device = device #type: ClusterUM3OutputDevice
+        self.device = device  # type: ClusterUM3OutputDevice
 
+    ##  Send the request to the printer and register a callback
     def run(self) -> None:
-        self.device.get("materials/", on_finished = self.sendMissingMaterials)
+        self.device.get("materials/", on_finished = self._onGetRemoteMaterials)
 
-    def sendMissingMaterials(self, reply: QNetworkReply) -> None:
-        if reply.attribute(QNetworkRequest.HttpStatusCodeAttribute) != 200: #Got an error from the HTTP request.
-            Logger.log("e", "Couldn't request current material storage on printer. Not syncing materials.")
+    ##  Process the materials reply from the printer.
+    #
+    #   \param reply The reply from the printer, a json file.
+    def _onGetRemoteMaterials(self, reply: QNetworkReply) -> None:
+
+        # Got an error from the HTTP request. If we did not receive a 200 something happened.
+        if reply.attribute(QNetworkRequest.HttpStatusCodeAttribute) != 200:
+            Logger.log("e", "Error fetching materials from printer: %s", reply.errorString())
             return
 
-        remote_materials_list = reply.readAll().data().decode("utf-8")
-        try:
-            remote_materials_list = json.loads(remote_materials_list)
-        except json.JSONDecodeError:
-            Logger.log("e", "Request material storage on printer: I didn't understand the printer's answer.")
-            return
-        try:
-            remote_materials_by_guid = {material["guid"]: material for material in remote_materials_list} #Index by GUID.
-        except KeyError:
-            Logger.log("e", "Request material storage on printer: Printer's answer was missing GUIDs.")
+        # Collect materials from the printer's reply and send the missing ones if needed.
+        remote_materials_by_guid = self._parseReply(reply)
+        if remote_materials_by_guid:
+            self._sendMissingMaterials(remote_materials_by_guid)
+
+    ##  Determine which materials should be updated and send them to the printer.
+    #
+    #   \param remote_materials_by_guid The remote materials by GUID.
+    def _sendMissingMaterials(self, remote_materials_by_guid: Dict[str, ClusterMaterial]) -> None:
+
+        # Collect local materials
+        local_materials_by_guid = self._getLocalMaterials()
+        if len(local_materials_by_guid) == 0:
+            Logger.log("d", "There are no local materials to synchronize with the printer.")
             return
 
-        container_registry = ContainerRegistry.getInstance()
-        local_materials_list = filter(lambda material: ("GUID" in material and "version" in material and "id" in material), container_registry.findContainersMetadata(type = "material"))
-        local_materials_by_guid = {material["GUID"]: material for material in local_materials_list if material["id"] == material["base_file"]}
-        for material in local_materials_list: #For each GUID get the material with the highest version number.
-            try:
-                if int(material["version"]) > local_materials_by_guid[material["GUID"]]["version"]:
-                    local_materials_by_guid[material["GUID"]] = material
-            except ValueError:
-                Logger.log("e", "Material {material_id} has invalid version number {number}.".format(material_id = material["id"], number = material["version"]))
-                continue
+        # Find out what materials are new or updated and must be sent to the printer
+        material_ids_to_send = self._determineMaterialsToSend(local_materials_by_guid, remote_materials_by_guid)
+        if len(material_ids_to_send) == 0:
+            Logger.log("d", "There are no remote materials to update.")
+            return
 
-        materials_to_send = set() #type: Set[Dict[str, Any]]
-        for guid, material in local_materials_by_guid.items():
-            if guid not in remote_materials_by_guid:
-                materials_to_send.add(material["id"])
-                continue
-            try:
-                if int(material["version"]) > remote_materials_by_guid[guid]["version"]:
-                    materials_to_send.add(material["id"])
-                    continue
-            except KeyError:
-                Logger.log("e", "Current material storage on printer was an invalid reply (missing version).")
-                return
+        # Send materials to the printer
+        self._sendMaterials(material_ids_to_send)
 
-        for file_path in Resources.getAllResourcesOfType(CuraApplication.ResourceTypes.MaterialInstanceContainer):
+    ##  From the local and remote materials, determine which ones should be synchronized.
+    #
+    #   Makes a Set of id's containing only the id's of the materials that are not on the printer yet or the ones that
+    #   are newer in Cura.
+    #
+    #   \param local_materials The local materials by GUID.
+    #   \param remote_materials The remote materials by GUID.
+    @staticmethod
+    def _determineMaterialsToSend(local_materials: Dict[str, LocalMaterial],
+                                  remote_materials: Dict[str, ClusterMaterial]) -> Set[str]:
+        return {
+            material.id
+            for guid, material in local_materials.items()
+            if guid not in remote_materials or material.version > remote_materials[guid].version
+        }
+
+    ##  Send the materials to the printer.
+    #
+    #   The given materials will be loaded from disk en sent to to printer.
+    #   The given id's will be matched with filenames of the locally stored materials.
+    #
+    #   \param materials_to_send A set with id's of materials that must be sent.
+    def _sendMaterials(self, materials_to_send: Set[str]) -> None:
+        file_paths = Resources.getAllResourcesOfType(CuraApplication.ResourceTypes.MaterialInstanceContainer)
+
+        # Find all local material files and send them if needed.
+        for file_path in file_paths:
             try:
                 mime_type = MimeTypeDatabase.getMimeTypeForFile(file_path)
             except MimeTypeDatabase.MimeTypeNotFoundError:
-                continue #Not the sort of file we'd like to send then.
-            _, file_name = os.path.split(file_path)
-            material_id = urllib.parse.unquote_plus(mime_type.stripExtension(file_name))
-            if material_id not in materials_to_send:
                 continue
 
-            parts = []
-            with open(file_path, "rb") as f:
-                parts.append(self.device._createFormPart("name=\"file\"; filename=\"{file_name}\"".format(file_name = file_name), f.read()))
-            signature_file_path = file_path + ".sig"
-            if os.path.exists(signature_file_path):
-                _, signature_file_name = os.path.split(signature_file_path)
-                with open(signature_file_path, "rb") as f:
-                    parts.append(self.device._createFormPart("name=\"signature_file\"; filename=\"{file_name}\"".format(file_name = signature_file_name), f.read()))
+            file_name = os.path.basename(file_path)
+            material_id = urllib.parse.unquote_plus(mime_type.stripExtension(file_name))
+            if material_id not in materials_to_send:
+                # If the material does not have to be sent we skip it.
+                continue
 
-            Logger.log("d", "Syncing material {material_id} with cluster.".format(material_id = material_id))
-            self.device.postFormWithParts(target = "materials/", parts = parts, on_finished = self.sendingFinished)
+            self._sendMaterialFile(file_path, file_name, material_id)
 
-    def sendingFinished(self, reply: QNetworkReply):
+    ##  Send a single material file to the printer.
+    #
+    #   Also add the material signature file if that is available.
+    #
+    #   \param file_path The path of the material file.
+    #   \param file_name The name of the material file.
+    #   \param material_id The ID of the material in the file.
+    def _sendMaterialFile(self, file_path: str, file_name: str, material_id: str) -> None:
+
+        parts = []
+
+        # Add the material file.
+        with open(file_path, "rb") as f:
+            parts.append(self.device.createFormPart("name=\"file\"; filename=\"{file_name}\""
+                                                    .format(file_name = file_name), f.read()))
+
+        # Add the material signature file if needed.
+        signature_file_path = "{}.sig".format(file_path)
+        if os.path.exists(signature_file_path):
+            signature_file_name = os.path.basename(signature_file_path)
+            with open(signature_file_path, "rb") as f:
+                parts.append(self.device.createFormPart("name=\"signature_file\"; filename=\"{file_name}\""
+                                                        .format(file_name = signature_file_name), f.read()))
+
+        Logger.log("d", "Syncing material {material_id} with cluster.".format(material_id = material_id))
+        self.device.postFormWithParts(target = "materials/", parts = parts, on_finished = self.sendingFinished)
+
+    ##  Check a reply from an upload to the printer and log an error when the call failed
+    @staticmethod
+    def sendingFinished(reply: QNetworkReply) -> None:
         if reply.attribute(QNetworkRequest.HttpStatusCodeAttribute) != 200:
-            Logger.log("e", "Received error code from printer when syncing material: {code}".format(code = reply.attribute(QNetworkRequest.HttpStatusCodeAttribute)))
-            Logger.log("e", reply.readAll().data().decode("utf-8"))
\ No newline at end of file
+            Logger.log("e", "Received error code from printer when syncing material: {code}, {text}".format(
+                code = reply.attribute(QNetworkRequest.HttpStatusCodeAttribute),
+                text = reply.errorString()
+            ))
+
+    ##  Parse the reply from the printer
+    #
+    #   Parses the reply to a "/materials" request to the printer
+    #
+    #   \return a dictionary of ClusterMaterial objects by GUID
+    #   \throw KeyError Raised when on of the materials does not include a valid guid
+    @classmethod
+    def _parseReply(cls, reply: QNetworkReply) -> Dict[str, ClusterMaterial]:
+        try:
+            remote_materials = json.loads(reply.readAll().data().decode("utf-8"))
+            return {material["guid"]: ClusterMaterial(**material) for material in remote_materials}
+        except UnicodeDecodeError:
+            Logger.log("e", "Request material storage on printer: I didn't understand the printer's answer.")
+        except json.JSONDecodeError:
+            Logger.log("e", "Request material storage on printer: I didn't understand the printer's answer.")
+        except ValueError:
+            Logger.log("e", "Request material storage on printer: Printer's answer had an incorrect value.")
+        except TypeError:
+            Logger.log("e", "Request material storage on printer: Printer's answer was missing a required value.")
+
+    ##  Retrieves a list of local materials
+    #
+    #   Only the new newest version of the local materials is returned
+    #
+    #   \return a dictionary of LocalMaterial objects by GUID
+    def _getLocalMaterials(self) -> Dict[str, LocalMaterial]:
+        result = {}  # type: Dict[str, LocalMaterial]
+        container_registry = Application.getInstance().getContainerRegistry()
+        material_containers = container_registry.findContainersMetadata(type = "material")
+
+        # Find the latest version of all material containers in the registry.
+        for material in material_containers:
+            try:
+                # material version must be an int
+                material["version"] = int(material["version"])
+
+                # Create a new local material
+                local_material = LocalMaterial(**material)
+
+                if local_material.GUID not in result or \
+                        local_material.version > result.get(local_material.GUID).version:
+                    result[local_material.GUID] = local_material
+
+            except KeyError:
+                Logger.logException("w", "Local material {} has missing values.".format(material["id"]))
+            except ValueError:
+                Logger.logException("w", "Local material {} has invalid values.".format(material["id"]))
+            except TypeError:
+                Logger.logException("w", "Local material {} has invalid values.".format(material["id"]))
+
+        return result
diff --git a/plugins/UM3NetworkPrinting/tests/TestSendMaterialJob.py b/plugins/UM3NetworkPrinting/tests/TestSendMaterialJob.py
new file mode 100644
index 0000000000..b669eb192a
--- /dev/null
+++ b/plugins/UM3NetworkPrinting/tests/TestSendMaterialJob.py
@@ -0,0 +1,190 @@
+# Copyright (c) 2018 Ultimaker B.V.
+# Copyright (c) 2018 Ultimaker B.V.
+# Cura is released under the terms of the LGPLv3 or higher.
+import io
+import json
+from unittest import TestCase, mock
+from unittest.mock import patch, call
+
+from PyQt5.QtCore import QByteArray
+
+from UM.MimeTypeDatabase import MimeType
+from UM.Application import Application
+from plugins.UM3NetworkPrinting.src.SendMaterialJob import SendMaterialJob
+
+
+@patch("builtins.open", lambda _, __: io.StringIO("<xml></xml>"))
+@patch("UM.MimeTypeDatabase.MimeTypeDatabase.getMimeTypeForFile",
+       lambda _: MimeType(name = "application/x-ultimaker-material-profile", comment = "Ultimaker Material Profile",
+                          suffixes = ["xml.fdm_material"]))
+@patch("UM.Resources.Resources.getAllResourcesOfType", lambda _: ["/materials/generic_pla_white.xml.fdm_material"])
+@patch("plugins.UM3NetworkPrinting.src.ClusterUM3OutputDevice")
+@patch("PyQt5.QtNetwork.QNetworkReply")
+class TestSendMaterialJob(TestCase):
+    _LOCAL_MATERIAL_WHITE = {"type": "material", "status": "unknown", "id": "generic_pla_white",
+                             "base_file": "generic_pla_white", "setting_version": "5", "name": "White PLA",
+                             "brand": "Generic", "material": "PLA", "color_name": "White",
+                             "GUID": "badb0ee7-87c8-4f3f-9398-938587b67dce", "version": "1", "color_code": "#ffffff",
+                             "description": "Test PLA White", "adhesion_info": "Use glue.", "approximate_diameter": "3",
+                             "properties": {"density": "1.00", "diameter": "2.85", "weight": "750"},
+                             "definition": "fdmprinter", "compatible": True}
+
+    _LOCAL_MATERIAL_BLACK = {"type": "material", "status": "unknown", "id": "generic_pla_black",
+                             "base_file": "generic_pla_black", "setting_version": "5", "name": "Yellow CPE",
+                             "brand": "Ultimaker", "material": "CPE", "color_name": "Black",
+                             "GUID": "5fbb362a-41f9-4818-bb43-15ea6df34aa4", "version": "1", "color_code": "#000000",
+                             "description": "Test PLA Black", "adhesion_info": "Use glue.", "approximate_diameter": "3",
+                             "properties": {"density": "1.01", "diameter": "2.85", "weight": "750"},
+                             "definition": "fdmprinter", "compatible": True}
+
+    _REMOTE_MATERIAL_WHITE = {
+        "guid": "badb0ee7-87c8-4f3f-9398-938587b67dce",
+        "material": "PLA",
+        "brand": "Generic",
+        "version": 1,
+        "color": "White",
+        "density": 1.00
+    }
+
+    _REMOTE_MATERIAL_BLACK = {
+        "guid": "5fbb362a-41f9-4818-bb43-15ea6df34aa4",
+        "material": "PLA",
+        "brand": "Generic",
+        "version": 2,
+        "color": "Black",
+        "density": 1.00
+    }
+
+    def test_run(self, device_mock, reply_mock):
+        job = SendMaterialJob(device_mock)
+        job.run()
+
+        # We expect the materials endpoint to be called when the job runs.
+        device_mock.get.assert_called_with("materials/", on_finished = job._onGetRemoteMaterials)
+
+    def test__onGetRemoteMaterials_withFailedRequest(self, reply_mock, device_mock):
+        reply_mock.attribute.return_value = 404
+        job = SendMaterialJob(device_mock)
+        job._onGetRemoteMaterials(reply_mock)
+
+        # We expect the device not to be called for any follow up.
+        self.assertEqual(0, device_mock.createFormPart.call_count)
+
+    def test__onGetRemoteMaterials_withWrongEncoding(self, reply_mock, device_mock):
+        reply_mock.attribute.return_value = 200
+        reply_mock.readAll.return_value = QByteArray(json.dumps([self._REMOTE_MATERIAL_WHITE]).encode("cp500"))
+        job = SendMaterialJob(device_mock)
+        job._onGetRemoteMaterials(reply_mock)
+
+        # Given that the parsing fails we do no expect the device to be called for any follow up.
+        self.assertEqual(0, device_mock.createFormPart.call_count)
+
+    def test__onGetRemoteMaterials_withBadJsonAnswer(self, reply_mock, device_mock):
+        reply_mock.attribute.return_value = 200
+        reply_mock.readAll.return_value = QByteArray(b"Six sick hicks nick six slick bricks with picks and sticks.")
+        job = SendMaterialJob(device_mock)
+        job._onGetRemoteMaterials(reply_mock)
+
+        # Given that the parsing fails we do no expect the device to be called for any follow up.
+        self.assertEqual(0, device_mock.createFormPart.call_count)
+
+    def test__onGetRemoteMaterials_withMissingGuidInRemoteMaterial(self, reply_mock, device_mock):
+        reply_mock.attribute.return_value = 200
+        remote_material_without_guid = self._REMOTE_MATERIAL_WHITE.copy()
+        del remote_material_without_guid["guid"]
+        reply_mock.readAll.return_value = QByteArray(json.dumps([remote_material_without_guid]).encode("ascii"))
+        job = SendMaterialJob(device_mock)
+        job._onGetRemoteMaterials(reply_mock)
+
+        # Given that parsing fails we do not expect the device to be called for any follow up.
+        self.assertEqual(0, device_mock.createFormPart.call_count)
+
+    @patch("cura.Settings.CuraContainerRegistry")
+    @patch("UM.Application")
+    def test__onGetRemoteMaterials_withInvalidVersionInLocalMaterial(self, application_mock, container_registry_mock,
+                                                                     reply_mock, device_mock):
+        reply_mock.attribute.return_value = 200
+        reply_mock.readAll.return_value = QByteArray(json.dumps([self._REMOTE_MATERIAL_WHITE]).encode("ascii"))
+
+        localMaterialWhiteWithInvalidVersion = self._LOCAL_MATERIAL_WHITE.copy()
+        localMaterialWhiteWithInvalidVersion["version"] = "one"
+        container_registry_mock.findContainersMetadata.return_value = [localMaterialWhiteWithInvalidVersion]
+
+        application_mock.getContainerRegistry.return_value = container_registry_mock
+
+        with mock.patch.object(Application, "getInstance", new = lambda: application_mock):
+            job = SendMaterialJob(device_mock)
+            job._onGetRemoteMaterials(reply_mock)
+
+        self.assertEqual(0, device_mock.createFormPart.call_count)
+
+    @patch("cura.Settings.CuraContainerRegistry")
+    @patch("UM.Application")
+    def test__onGetRemoteMaterials_withNoUpdate(self, application_mock, container_registry_mock, reply_mock,
+                                                device_mock):
+        application_mock.getContainerRegistry.return_value = container_registry_mock
+
+        device_mock.createFormPart.return_value = "_xXx_"
+
+        container_registry_mock.findContainersMetadata.return_value = [self._LOCAL_MATERIAL_WHITE]
+
+        reply_mock.attribute.return_value = 200
+        reply_mock.readAll.return_value = QByteArray(json.dumps([self._REMOTE_MATERIAL_WHITE]).encode("ascii"))
+
+        with mock.patch.object(Application, "getInstance", new = lambda: application_mock):
+            job = SendMaterialJob(device_mock)
+            job._onGetRemoteMaterials(reply_mock)
+
+        self.assertEqual(0, device_mock.createFormPart.call_count)
+        self.assertEqual(0, device_mock.postFormWithParts.call_count)
+
+    @patch("cura.Settings.CuraContainerRegistry")
+    @patch("UM.Application")
+    def test__onGetRemoteMaterials_withUpdatedMaterial(self, application_mock, container_registry_mock, reply_mock,
+                                                       device_mock):
+        application_mock.getContainerRegistry.return_value = container_registry_mock
+
+        device_mock.createFormPart.return_value = "_xXx_"
+
+        localMaterialWhiteWithHigherVersion = self._LOCAL_MATERIAL_WHITE.copy()
+        localMaterialWhiteWithHigherVersion["version"] = "2"
+        container_registry_mock.findContainersMetadata.return_value = [localMaterialWhiteWithHigherVersion]
+
+        reply_mock.attribute.return_value = 200
+        reply_mock.readAll.return_value = QByteArray(json.dumps([self._REMOTE_MATERIAL_WHITE]).encode("ascii"))
+
+        with mock.patch.object(Application, "getInstance", new = lambda: application_mock):
+            job = SendMaterialJob(device_mock)
+            job._onGetRemoteMaterials(reply_mock)
+
+        self.assertEqual(1, device_mock.createFormPart.call_count)
+        self.assertEqual(1, device_mock.postFormWithParts.call_count)
+        self.assertEquals(
+            [call.createFormPart("name=\"file\"; filename=\"generic_pla_white.xml.fdm_material\"", "<xml></xml>"),
+             call.postFormWithParts(target = "materials/", parts = ["_xXx_"], on_finished = job.sendingFinished)],
+            device_mock.method_calls)
+
+    @patch("cura.Settings.CuraContainerRegistry")
+    @patch("UM.Application")
+    def test__onGetRemoteMaterials_withNewMaterial(self, application_mock, container_registry_mock, reply_mock,
+                                                   device_mock):
+        application_mock.getContainerRegistry.return_value = container_registry_mock
+
+        device_mock.createFormPart.return_value = "_xXx_"
+
+        container_registry_mock.findContainersMetadata.return_value = [self._LOCAL_MATERIAL_WHITE,
+                                                                       self._LOCAL_MATERIAL_BLACK]
+
+        reply_mock.attribute.return_value = 200
+        reply_mock.readAll.return_value = QByteArray(json.dumps([self._REMOTE_MATERIAL_BLACK]).encode("ascii"))
+
+        with mock.patch.object(Application, "getInstance", new = lambda: application_mock):
+            job = SendMaterialJob(device_mock)
+            job._onGetRemoteMaterials(reply_mock)
+
+        self.assertEqual(1, device_mock.createFormPart.call_count)
+        self.assertEqual(1, device_mock.postFormWithParts.call_count)
+        self.assertEquals(
+            [call.createFormPart("name=\"file\"; filename=\"generic_pla_white.xml.fdm_material\"", "<xml></xml>"),
+             call.postFormWithParts(target = "materials/", parts = ["_xXx_"], on_finished = job.sendingFinished)],
+            device_mock.method_calls)