diff --git a/src/libslic3r/SLAPrint.cpp b/src/libslic3r/SLAPrint.cpp
index 2a1ae74d7..2c080ec3d 100644
--- a/src/libslic3r/SLAPrint.cpp
+++ b/src/libslic3r/SLAPrint.cpp
@@ -1372,7 +1372,12 @@ void SLAPrint::process()
         m_print_statistics.fast_layers_count = fast_layers;
         m_print_statistics.slow_layers_count = slow_layers;
 
+#if ENABLE_THUMBNAIL_GENERATOR
+        // second argument set to -3 to differentiate it from the same call made into slice_supports()
+        m_report_status(*this, -3, "", SlicingStatus::RELOAD_SLA_PREVIEW);
+#else
         m_report_status(*this, -2, "", SlicingStatus::RELOAD_SLA_PREVIEW);
+#endif // ENABLE_THUMBNAIL_GENERATOR
     };
 
     // Rasterizing the model objects, and their supports
diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index a99b210ac..914084bb6 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -1647,7 +1647,7 @@ void GLCanvas3D::render()
 }
 
 #if ENABLE_THUMBNAIL_GENERATOR
-void GLCanvas3D::render_thumbnail(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only)
+void GLCanvas3D::render_thumbnail(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only)
 {
     auto is_visible = [](const GLVolume& v) -> bool {
         bool ret = v.printable;
@@ -1664,8 +1664,11 @@ void GLCanvas3D::render_thumbnail(ThumbnailData& thumbnail_data, unsigned int w,
 
     for (GLVolume* vol : m_volumes.volumes)
     {
-        if (!printable_only || is_visible(*vol))
-            visible_volumes.push_back(vol);
+        if (!vol->is_modifier && (!parts_only || (vol->composite_id.volume_id >= 0)))
+        {
+            if (!printable_only || is_visible(*vol))
+                visible_volumes.push_back(vol);
+        }
     }
 
     if (visible_volumes.empty())
@@ -1697,6 +1700,25 @@ void GLCanvas3D::render_thumbnail(ThumbnailData& thumbnail_data, unsigned int w,
     glsafe(::glDisable(GL_LIGHTING));
     glsafe(::glReadPixels(0, 0, thumbnail_data.width, thumbnail_data.height, GL_RGBA, GL_UNSIGNED_BYTE, (void*)thumbnail_data.pixels.data()));
 
+#if 0
+    // debug export of generated image
+    wxImage image(thumbnail_data.width, thumbnail_data.height);
+    image.InitAlpha();
+
+    for (unsigned int r = 0; r < thumbnail_data.height; ++r)
+    {
+        unsigned int rr = (thumbnail_data.height - 1 - r) * thumbnail_data.width;
+        for (unsigned int c = 0; c < thumbnail_data.width; ++c)
+        {
+            unsigned char* px = thumbnail_data.pixels.data() + 4 * (rr + c);
+            image.SetRGB((int)c, (int)r, px[0], px[1], px[2]);
+            image.SetAlpha((int)c, (int)r, px[3]);
+        }
+    }
+
+    image.SaveFile("C:/test.png", wxBITMAP_TYPE_PNG);
+#endif 
+
     // restore the framebuffer size to avoid flickering on the 3D scene
     const Size& cnv_size = get_canvas_size();
     m_camera.apply_viewport(0, 0, cnv_size.get_width(), cnv_size.get_height());
diff --git a/src/slic3r/GUI/GLCanvas3D.hpp b/src/slic3r/GUI/GLCanvas3D.hpp
index 611e9a932..5b06b6311 100644
--- a/src/slic3r/GUI/GLCanvas3D.hpp
+++ b/src/slic3r/GUI/GLCanvas3D.hpp
@@ -523,7 +523,9 @@ public:
 
     void render();
 #if ENABLE_THUMBNAIL_GENERATOR
-    void render_thumbnail(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only);
+    // printable_only == false -> render also non printable volumes as grayed
+    // parts_only == false -> render also sla support and pad
+    void render_thumbnail(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only);
 #endif // ENABLE_THUMBNAIL_GENERATOR
 
     void select_all();
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 0ebd208fa..008a6eaa3 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -1928,7 +1928,7 @@ struct Plater::priv
     bool can_reload_from_disk() const;
 
 #if ENABLE_THUMBNAIL_GENERATOR
-    void generate_thumbnail(unsigned int w, unsigned int h, bool printable_only);
+    void generate_thumbnail(ThumbnailData& data, unsigned int w, unsigned int h, bool printable_only, bool parts_only);
 #endif // ENABLE_THUMBNAIL_GENERATOR
 
     void msw_rescale_object_menu();
@@ -3050,9 +3050,12 @@ bool Plater::priv::restart_background_process(unsigned int state)
         {
             // update thumbnail data
             if (this->printer_technology == ptFFF)
-                generate_thumbnail(THUMBNAIL_SIZE_FFF.first, THUMBNAIL_SIZE_FFF.second, true);
+                // for ptFFF we need to generate the thumbnail before the export of gcode starts
+                generate_thumbnail(this->thumbnail_data, THUMBNAIL_SIZE_FFF.first, THUMBNAIL_SIZE_FFF.second, true, true);
             else if (this->printer_technology == ptSLA)
-                generate_thumbnail(THUMBNAIL_SIZE_SLA.first, THUMBNAIL_SIZE_SLA.second, true);
+                // for ptSLA generate thumbnail without supports and pad (not yet calculated)
+                // to render also supports and pad see on_slicing_update()
+                generate_thumbnail(this->thumbnail_data, THUMBNAIL_SIZE_SLA.first, THUMBNAIL_SIZE_SLA.second, true, true);
         }
 #endif // ENABLE_THUMBNAIL_GENERATOR
         // The print is valid and it can be started.
@@ -3392,13 +3395,14 @@ void Plater::priv::on_slicing_update(SlicingStatusEvent &evt)
     } else if (evt.status.flags & PrintBase::SlicingStatus::RELOAD_SLA_PREVIEW) {
         // Update the SLA preview. Only called if not RELOAD_SLA_SUPPORT_POINTS, as the block above will refresh the preview anyways.
         this->preview->reload_print();
+/*
 #if ENABLE_THUMBNAIL_GENERATOR
         // update thumbnail data
-        if (this->printer_technology == ptFFF)
-            generate_thumbnail(THUMBNAIL_SIZE_FFF.first, THUMBNAIL_SIZE_FFF.second, true);
-        else if (this->printer_technology == ptSLA)
-            generate_thumbnail(THUMBNAIL_SIZE_SLA.first, THUMBNAIL_SIZE_SLA.second, true);
+        // for ptSLA generate the thumbnail after supports and pad have been calculated to have them rendered
+        if ((this->printer_technology == ptSLA) && (evt.status.percent == -3))
+            generate_thumbnail(this->thumbnail_data, THUMBNAIL_SIZE_SLA.first, THUMBNAIL_SIZE_SLA.second, true, false);
 #endif // ENABLE_THUMBNAIL_GENERATOR
+*/
     }
 }
 
@@ -3625,9 +3629,9 @@ bool Plater::priv::init_object_menu()
 }
 
 #if ENABLE_THUMBNAIL_GENERATOR
-void Plater::priv::generate_thumbnail(unsigned int w, unsigned int h, bool printable_only)
+void Plater::priv::generate_thumbnail(ThumbnailData& data, unsigned int w, unsigned int h, bool printable_only, bool parts_only)
 {
-    view3D->get_canvas3d()->render_thumbnail(thumbnail_data, w, h, printable_only);
+    view3D->get_canvas3d()->render_thumbnail(data, w, h, printable_only, parts_only);
 }
 #endif // ENABLE_THUMBNAIL_GENERATOR
 
@@ -4670,8 +4674,9 @@ void Plater::export_3mf(const boost::filesystem::path& output_path)
     const std::string path_u8 = into_u8(path);
     wxBusyCursor wait;
 #if ENABLE_THUMBNAIL_GENERATOR
-    p->generate_thumbnail(THUMBNAIL_SIZE_3MF.first, THUMBNAIL_SIZE_3MF.second, false);
-    if (Slic3r::store_3mf(path_u8.c_str(), &p->model, export_config ? &cfg : nullptr, &p->thumbnail_data)) {
+    ThumbnailData thumbnail_data;
+    p->generate_thumbnail(thumbnail_data, THUMBNAIL_SIZE_3MF.first, THUMBNAIL_SIZE_3MF.second, false, true);
+    if (Slic3r::store_3mf(path_u8.c_str(), &p->model, export_config ? &cfg : nullptr, &thumbnail_data)) {
 #else
     if (Slic3r::store_3mf(path_u8.c_str(), &p->model, export_config ? &cfg : nullptr)) {
 #endif // ENABLE_THUMBNAIL_GENERATOR