diff --git a/src/libslic3r/Format/3mf.cpp b/src/libslic3r/Format/3mf.cpp
index f4b16b3650..e8fde1fbb1 100644
--- a/src/libslic3r/Format/3mf.cpp
+++ b/src/libslic3r/Format/3mf.cpp
@@ -1419,23 +1419,31 @@ namespace Slic3r {
                 std::vector<sla::SupportPoint> sla_support_points;
 
                 if (version == 0) {
+                    assert(object_data_points.size() % 3 == 0);
                     for (unsigned int i=0; i<object_data_points.size(); i+=3)
-                    sla_support_points.push_back(sla::SupportPoint{Vec3f(
+                        sla_support_points.push_back(sla::SupportPoint{Vec3f(
                                                     float(std::atof(object_data_points[i+0].c_str())),
                                                     float(std::atof(object_data_points[i+1].c_str())),
 													float(std::atof(object_data_points[i+2].c_str()))),
                                                     0.4f});
                 }
                 if (version == 1) {
+                    auto get_support_point_type = [](double val)->sla::SupportPointType{
+                        return (std::abs(val - 1.) < EPSILON) ? sla::SupportPointType::island :
+                               (std::abs(val - 2.) < EPSILON) ? sla::SupportPointType::manual_add :
+                               //(std::abs(val - 3.) < EPSILON) ? sla::SupportPointType::slope :
+                                sla::SupportPointType::slope; // default for previous version of store points
+                    };
+                    assert(object_data_points.size() % 5 == 0);
                     for (unsigned int i=0; i<object_data_points.size(); i+=5)
-                    sla_support_points.push_back(sla::SupportPoint{Vec3f(
-                                                    float(std::atof(object_data_points[i+0].c_str())),
-                                                    float(std::atof(object_data_points[i+1].c_str())),
-                                                    float(std::atof(object_data_points[i+2].c_str()))),
-                                                float(std::atof(object_data_points[i+3].c_str())),
-												//FIXME storing boolean as 0 / 1 and importing it as float.
-                                                std::abs(std::atof(object_data_points[i+4].c_str()) - 1.) < EPSILON ?
-                                                    sla::SupportPointType::island : sla::SupportPointType::manual_add});
+                        sla_support_points.push_back(
+                            sla::SupportPoint{
+                                Vec3f{float(std::atof(object_data_points[i+0].c_str())),
+                                      float(std::atof(object_data_points[i+1].c_str())),
+                                      float(std::atof(object_data_points[i+2].c_str()))},
+                                float(std::atof(object_data_points[i+3].c_str())),
+                                get_support_point_type(std::atof(object_data_points[i+4].c_str()))
+                            });
                 }
 
                 if (!sla_support_points.empty())
@@ -3541,10 +3549,22 @@ namespace Slic3r {
             if (!sla_support_points.empty()) {
                 sprintf(buffer, "object_id=%d|", count);
                 out += buffer;
-
+                auto support_point_type_to_float = [](sla::SupportPointType t) -> float {
+                    switch (t) {
+                    case Slic3r::sla::SupportPointType::manual_add: return 2.f;
+                    case Slic3r::sla::SupportPointType::island: return 1.f;
+                    case Slic3r::sla::SupportPointType::slope: return 3.f;
+                    default: assert(false); return 0.f;
+                    }
+                };
                 // Store the layer height profile as a single space separated list.
                 for (size_t i = 0; i < sla_support_points.size(); ++i) {
-                    sprintf(buffer, (i==0 ? "%f %f %f %f %f" : " %f %f %f %f %f"),  sla_support_points[i].pos(0), sla_support_points[i].pos(1), sla_support_points[i].pos(2), sla_support_points[i].head_front_radius, (float)(sla_support_points[i].is_island()));
+                    sprintf(buffer, (i==0 ? "%f %f %f %f %f" : " %f %f %f %f %f"), 
+                        sla_support_points[i].pos(0), 
+                        sla_support_points[i].pos(1), 
+                        sla_support_points[i].pos(2),
+                        sla_support_points[i].head_front_radius,
+                        support_point_type_to_float(sla_support_points[i].type));
                     out += buffer;
                 }
                 out += "\n";
diff --git a/src/libslic3r/Format/3mf.hpp b/src/libslic3r/Format/3mf.hpp
index 78f95b7db0..b2e3746fd2 100644
--- a/src/libslic3r/Format/3mf.hpp
+++ b/src/libslic3r/Format/3mf.hpp
@@ -19,7 +19,18 @@ namespace Slic3r {
      * version 1 :  ThreeMF_support_points_version=1
                     object_id=1|-12.055421 -2.658771 10.000000 0.4 0.0
                     object_id=2|-14.051745 -3.570338 5.000000 0.6 1.0
-        // introduced header with version number; x,y,z,head_size,is_new_island)
+        // introduced header with version number; x,y,z,head_size,type)
+        // before 2.9.1 fifth float means is_island (bool flag) -> value from 0.9999f to 1.0001f means it is support for island otherwise not. User edited points has always value zero.
+        // since 2.9.1 fifth float means type -> starts show user edited points
+        // type range value meaning
+        // (float is used only for compatibility, string will be better)
+        // from    | to     | meaning
+        // --------------------------------
+        // 0.9999f | 1.0001 | island (no change)
+        // 1.9999f | 2.0001 | manual edited points loose info about island
+        // 2.9999f | 3.0001 | generated point by slope ration
+        // all other values are readed also as slope type
+
     */
 
     enum {