diff --git a/src/libslic3r/SLA/EigenMesh3D.hpp b/src/libslic3r/SLA/EigenMesh3D.hpp
index e8b869bb4..bcf94ec16 100644
--- a/src/libslic3r/SLA/EigenMesh3D.hpp
+++ b/src/libslic3r/SLA/EigenMesh3D.hpp
@@ -101,6 +101,9 @@ public:
 
     // Iterates over hits and holes and returns the true hit, possibly
     // on the inside of a hole.
+    // This function is currently not used anywhere, it was written when the
+    // holes were subtracted on slices, that is, before we started using CGAL
+    // to actually cut the holes into the mesh.
     hit_result filter_hits(const std::vector<EigenMesh3D::hit_result>& obj_hits) const;
 
     class si_result {
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoHollow.cpp b/src/slic3r/GUI/Gizmos/GLGizmoHollow.cpp
index 0027fb8be..0a3a6f898 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoHollow.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoHollow.cpp
@@ -100,16 +100,11 @@ void GLGizmoHollow::on_render() const
         return;
     }
 
-    // !!! is it necessary?
-    //const_cast<GLGizmoHollow*>(this)->m_c->update_from_backend(m_parent, m_c->m_model_object);
-
     glsafe(::glEnable(GL_BLEND));
     glsafe(::glEnable(GL_DEPTH_TEST));
 
     m_z_shift = selection.get_volume(*selection.get_volume_idxs().begin())->get_sla_shift_z();
 
-    render_hollowed_mesh();
-
     if (m_quadric != nullptr && selection.is_from_single_instance())
         render_points(selection, false);
 
@@ -121,28 +116,6 @@ void GLGizmoHollow::on_render() const
 
 
 
-void GLGizmoHollow::render_hollowed_mesh() const
-{
-    /*if (m_c->m_volume_with_cavity) {
-        m_c->m_volume_with_cavity->set_sla_shift_z(m_z_shift);
-        m_parent.get_shader().start_using();
-
-        GLint current_program_id;
-        glsafe(::glGetIntegerv(GL_CURRENT_PROGRAM, &current_program_id));
-        GLint color_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "uniform_color") : -1;
-        GLint print_box_detection_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "print_box.volume_detection") : -1;
-        GLint print_box_worldmatrix_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "print_box.volume_world_matrix") : -1;
-        glcheck();
-        m_c->m_volume_with_cavity->set_render_color();
-        const Geometry::Transformation& volume_trafo = m_c->m_model_object->volumes.front()->get_transformation();
-        m_c->m_volume_with_cavity->set_volume_transformation(volume_trafo);
-        m_c->m_volume_with_cavity->set_instance_transformation(m_c->m_model_object->instances[size_t(m_c->m_active_instance)]->get_transformation());
-        m_c->m_volume_with_cavity->render(color_id, print_box_detection_id, print_box_worldmatrix_id);
-        m_parent.get_shader().stop_using();
-    }*/
-}
-
-
 void GLGizmoHollow::render_clipping_plane(const Selection& selection) const
 {
     if (m_c->m_clipping_plane_distance == 0.f)
@@ -170,11 +143,6 @@ void GLGizmoHollow::render_clipping_plane(const Selection& selection) const
     m_c->m_object_clipper->set_plane(*m_c->m_clipping_plane);
     m_c->m_object_clipper->set_transformation(trafo);
 
-
-    // Next, ask the backend if supports are already calculated. If so, we are gonna cut them too.
-    //if (m_c->m_print_object_idx < 0)
-    //    m_c->update_from_backend(m_parent, m_c->m_model_object);
-
     if (m_c->m_print_object_idx >= 0) {
         const SLAPrintObject* print_object = m_parent.sla_print()->objects()[m_c->m_print_object_idx];
 
@@ -230,7 +198,6 @@ void GLGizmoHollow::on_render_for_picking() const
 
     glsafe(::glEnable(GL_DEPTH_TEST));
     render_points(selection, true);
-    render_hollowed_mesh();
 }
 
 void GLGizmoHollow::render_points(const Selection& selection, bool picking) const
@@ -344,10 +311,6 @@ bool GLGizmoHollow::unproject_on_mesh(const Vec2d& mouse_pos, std::pair<Vec3f, V
     if (! m_c->m_mesh_raycaster)
         return false;
 
-    // if the gizmo doesn't have the V, F structures for igl, calculate them first:
-    // !!! is it really necessary?
-    //m_c->update_from_backend(m_parent, m_c->m_model_object);
-
     const Camera& camera = m_parent.get_camera();
     const Selection& selection = m_parent.get_selection();
     const GLVolume* volume = selection.get_volume(*selection.get_volume_idxs().begin());
@@ -562,87 +525,15 @@ void GLGizmoHollow::on_update(const UpdateData& data)
     }
 }
 
-std::pair<const TriangleMesh *, sla::HollowingConfig> GLGizmoHollow::get_hollowing_parameters() const
-{
-    // FIXME this function is probably obsolete, caller could
-    // get the data from model config himself
-    auto opts = get_config_options({"hollowing_min_thickness", "hollowing_quality", "hollowing_closing_distance"});
-    double offset = static_cast<const ConfigOptionFloat*>(opts[0].first)->value;
-    double quality = static_cast<const ConfigOptionFloat*>(opts[1].first)->value;
-    double closing_d = static_cast<const ConfigOptionFloat*>(opts[2].first)->value;
-    return std::make_pair(m_c->m_mesh, sla::HollowingConfig{offset, quality, closing_d});
-}
-
-void GLGizmoHollow::update_mesh_raycaster(std::unique_ptr<MeshRaycaster> &&rc)
-{
-    m_c->m_mesh_raycaster = std::move(rc);
-    m_c->m_object_clipper.reset();
-    //m_c->m_volume_with_cavity.reset();
-}
 
 void GLGizmoHollow::hollow_mesh(bool postpone_error_messages)
 {
-    // Trigger a UI job to hollow the mesh.
-   // wxGetApp().plater()->hollow();
-
     wxGetApp().CallAfter([this, postpone_error_messages]() {
         wxGetApp().plater()->reslice_SLA_hollowing(*m_c->m_model_object, postpone_error_messages);
     });
 }
 
 
-void GLGizmoHollow::update_hollowed_mesh(std::unique_ptr<TriangleMesh> &&mesh)
-{
-    // Called from Plater when the UI job finishes
-    /*m_c->m_cavity_mesh = std::move(mesh);
-
-    if(m_c->m_cavity_mesh) {
-        // First subtract the holes:
-        if (! m_c->m_model_object->sla_drain_holes.empty()) {
-            TriangleMesh holes_mesh;
-            for (const sla::DrainHole& hole : m_c->m_model_object->sla_drain_holes) {
-                TriangleMesh hole_mesh = make_cylinder(hole.radius, hole.height, 2*M_PI/32);
-
-                Vec3d scaling = m_c->m_model_object->instances[m_c->m_active_instance]->get_scaling_factor();
-                Vec3d normal_transformed = Vec3d(hole.normal(0)/scaling(0), hole.normal(1)/scaling(1), hole.normal(2)/scaling(2));
-                normal_transformed.normalize();
-
-                // Rotate the cylinder appropriately
-                Eigen::Quaterniond q;
-                Transform3d m = Transform3d::Identity();
-                m.matrix().block(0, 0, 3, 3) = q.setFromTwoVectors(Vec3d::UnitZ(), normal_transformed).toRotationMatrix();
-                hole_mesh.transform(m);
-
-                // If the instance is scaled, undo the scaling of the hole
-                hole_mesh.scale(Vec3d(1/scaling(0), 1/scaling(1), 1/scaling(2)));
-
-                // Translate the hole into position and merge with the others
-                hole_mesh.translate(hole.pos);
-                holes_mesh.merge(hole_mesh);
-                holes_mesh.repair();
-            }
-            MeshBoolean::minus(*m_c->m_cavity_mesh.get(), holes_mesh);
-        }
-
-        // create a new GLVolume that only has the cavity inside
-        m_c->m_volume_with_cavity.reset(new GLVolume(GLVolume::MODEL_COLOR[2]));
-        m_c->m_volume_with_cavity->indexed_vertex_array.load_mesh(*m_c->m_cavity_mesh.get());
-        m_c->m_volume_with_cavity->finalize_geometry(true);
-        m_c->m_volume_with_cavity->force_transparent = false;
-
-        m_parent.toggle_model_objects_visibility(false, m_c->m_model_object, m_c->m_active_instance);
-        m_parent.toggle_sla_auxiliaries_visibility(true, m_c->m_model_object, m_c->m_active_instance);
-
-        // Reset raycaster so it works with the new mesh:
-        m_c->m_mesh_raycaster.reset(new MeshRaycaster(*m_c->mesh()));
-    }
-
-    if (m_c->m_clipping_plane_distance == 0.f) {
-        m_c->m_clipping_plane_distance = 0.5f;
-        update_clipping_plane();
-    }*/
-}
-
 std::vector<std::pair<const ConfigOption*, const ConfigOptionDef*>> GLGizmoHollow::get_config_options(const std::vector<std::string>& keys) const
 {
     std::vector<std::pair<const ConfigOption*, const ConfigOptionDef*>> out;
@@ -830,7 +721,6 @@ RENDER_AGAIN:
     bool remove_selected = false;
     bool remove_all = false;
 
-   // m_imgui->text(" "); // vertical gap
     ImGui::Separator();
 
     float diameter_upper_cap = 15.;
@@ -1014,10 +904,6 @@ void GLGizmoHollow::on_set_state()
             m_parent.toggle_model_objects_visibility(true, m_c->m_model_object, m_c->m_active_instance);
             m_parent.toggle_sla_auxiliaries_visibility(m_show_supports, m_c->m_model_object, m_c->m_active_instance);
         }
-
-        // Set default head diameter from config.
-        //const DynamicPrintConfig& cfg = wxGetApp().preset_bundle->sla_prints.get_edited_preset().config;
-        //m_new_hole_radius = static_cast<const ConfigOptionFloat*>(cfg.option("support_head_front_diameter"))->value;
     }
     if (m_state == Off && m_old_state != Off) { // the gizmo was just turned Off
         //Plater::TakeSnapshot snapshot(wxGetApp().plater(), _(L("SLA gizmo turned off")));
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoHollow.hpp b/src/slic3r/GUI/Gizmos/GLGizmoHollow.hpp
index bc4549a0e..3aafcbf55 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoHollow.hpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoHollow.hpp
@@ -36,11 +36,6 @@ public:
     void delete_selected_points();
     ClippingPlane get_sla_clipping_plane() const;
     
-    
-    std::pair<const TriangleMesh *, sla::HollowingConfig> get_hollowing_parameters() const;
-    void update_mesh_raycaster(std::unique_ptr<MeshRaycaster> &&rc);
-    void update_hollowed_mesh(std::unique_ptr<TriangleMesh> &&mesh);
-
     bool is_selection_rectangle_dragging() const { return m_selection_rectangle.is_dragging(); }
     void update_clipping_plane(bool keep_normal = false) const;
     void set_common_data_ptr(CommonGizmosData* ptr) { m_c = ptr; }
@@ -53,7 +48,6 @@ private:
 
     void render_points(const Selection& selection, bool picking = false) const;
     void render_clipping_plane(const Selection& selection) const;
-    void render_hollowed_mesh() const;
     void hollow_mesh(bool postpone_error_messages = false);
     bool unsaved_changes() const;
 
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp b/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp
index fa8de30ca..ab0b9b5d6 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp
@@ -107,8 +107,6 @@ void GLGizmoSlaSupports::on_render() const
 
     m_z_shift = selection.get_volume(*selection.get_volume_idxs().begin())->get_sla_shift_z();
 
-    render_hollowed_mesh();
-
     if (m_quadric != nullptr && selection.is_from_single_instance())
         render_points(selection, false);
 
@@ -120,29 +118,6 @@ void GLGizmoSlaSupports::on_render() const
 
 
 
-void GLGizmoSlaSupports::render_hollowed_mesh() const
-{
-    /*if (m_c->m_volume_with_cavity) {
-        m_c->m_volume_with_cavity->set_sla_shift_z(m_z_shift);
-        m_parent.get_shader().start_using();
-
-        GLint current_program_id;
-        glsafe(::glGetIntegerv(GL_CURRENT_PROGRAM, &current_program_id));
-        GLint color_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "uniform_color") : -1;
-        GLint print_box_detection_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "print_box.volume_detection") : -1;
-        GLint print_box_worldmatrix_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "print_box.volume_world_matrix") : -1;
-        glcheck();
-        m_c->m_volume_with_cavity->set_render_color();
-        const Geometry::Transformation& volume_trafo = m_c->m_model_object->volumes.front()->get_transformation();
-        m_c->m_volume_with_cavity->set_volume_transformation(volume_trafo);
-        m_c->m_volume_with_cavity->set_instance_transformation(m_c->m_model_object->instances[size_t(m_c->m_active_instance)]->get_transformation());
-        m_c->m_volume_with_cavity->render(color_id, print_box_detection_id, print_box_worldmatrix_id);
-        m_parent.get_shader().stop_using();
-    }*/
-}
-
-
-
 void GLGizmoSlaSupports::render_clipping_plane(const Selection& selection) const
 {
     if (m_c->m_clipping_plane_distance == 0.f || m_c->m_mesh->empty())
@@ -239,7 +214,6 @@ void GLGizmoSlaSupports::on_render_for_picking() const
 
     glsafe(::glEnable(GL_DEPTH_TEST));
     render_points(selection, true);
-    render_hollowed_mesh();
 }
 
 void GLGizmoSlaSupports::render_points(const Selection& selection, bool picking) const
@@ -628,8 +602,6 @@ void GLGizmoSlaSupports::delete_selected_points(bool force)
     }
 
     select_point(NoPoints);
-
-    //m_parent.post_event(SimpleEvent(EVT_GLCANVAS_SCHEDULE_BACKGROUND_PROCESS));
 }
 
 void GLGizmoSlaSupports::on_update(const UpdateData& data)
@@ -644,8 +616,6 @@ void GLGizmoSlaSupports::on_update(const UpdateData& data)
             m_editing_cache[m_hover_id].support_point.pos = pos_and_normal.first;
             m_editing_cache[m_hover_id].support_point.is_new_island = false;
             m_editing_cache[m_hover_id].normal = pos_and_normal.second;
-            // Do not update immediately, wait until the mouse is released.
-            // m_parent.post_event(SimpleEvent(EVT_GLCANVAS_SCHEDULE_BACKGROUND_PROCESS));
         }
     }
 }
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.hpp b/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.hpp
index deddabe5f..bd48ecd65 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.hpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.hpp
@@ -93,7 +93,6 @@ private:
     //void render_selection_rectangle() const;
     void render_points(const Selection& selection, bool picking = false) const;
     void render_clipping_plane(const Selection& selection) const;
-    void render_hollowed_mesh() const;
     bool unsaved_changes() const;
 
     bool m_lock_unique_islands = false;
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 6fc6ab86c..ed400bab8 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -86,8 +86,6 @@
 #include "WipeTowerDialog.hpp"
 #include "libslic3r/CustomGCode.hpp"
 
-#include "Gizmos/GLGizmoHollow.hpp"
-
 using boost::optional;
 namespace fs = boost::filesystem;
 using Slic3r::_3DScene;
@@ -1555,8 +1553,7 @@ struct Plater::priv
 
     enum class Jobs : size_t {
         Arrange,
-        Rotoptimize,
-        Hollow
+        Rotoptimize
     };
 
     class ArrangeJob : public PlaterJob
@@ -1700,23 +1697,6 @@ struct Plater::priv
         void process() override;
     };
 
-    // FIXME: This should be removed, as well as the #include of the gizmo
-    class HollowJob : public PlaterJob
-    {
-    public:
-        using PlaterJob::PlaterJob;
-        void prepare() override;
-        void process() override;
-        void finalize() override;
-    private:
-        GLGizmoHollow * get_gizmo();
-        const GLGizmoHollow * get_gizmo() const;
-        
-        std::unique_ptr<TriangleMesh> m_output_mesh;
-        std::unique_ptr<MeshRaycaster> m_output_raycaster;
-        const TriangleMesh* m_object_mesh = nullptr;
-        sla::HollowingConfig m_cfg;
-    };
 
     // Jobs defined inside the group class will be managed so that only one can
     // run at a time. Also, the background process will be stopped if a job is
@@ -1729,7 +1709,6 @@ struct Plater::priv
 
         ArrangeJob arrange_job{m_plater};
         RotoptimizeJob rotoptimize_job{m_plater};
-        HollowJob hollow_job{m_plater};
 
         // To create a new job, just define a new subclass of Job, implement
         // the process and the optional prepare() and finalize() methods
@@ -1737,8 +1716,7 @@ struct Plater::priv
         // if it cannot run concurrently with other jobs in this group
 
         std::vector<std::reference_wrapper<Job>> m_jobs{arrange_job,
-                                                        rotoptimize_job,
-                                                        hollow_job};
+                                                        rotoptimize_job};
 
     public:
         ExclusiveJobGroup(priv *_plater) : m_plater(_plater) {}
@@ -1841,7 +1819,6 @@ struct Plater::priv
     void reset();
     void mirror(Axis axis);
     void arrange();
-    void hollow();
     void sla_optimize_rotation();
     void split_object();
     void split_volume();
@@ -2757,11 +2734,6 @@ void Plater::priv::arrange()
     m_ui_jobs.start(Jobs::Arrange);
 }
 
-void Plater::priv::hollow()
-{
-    this->take_snapshot(_(L("Hollow")));
-    m_ui_jobs.start(Jobs::Hollow);
-}
 
 // This method will find an optimal orientation for the currently selected item
 // Very similar in nature to the arrange method above...
@@ -2894,67 +2866,6 @@ void Plater::priv::RotoptimizeJob::process()
                                  : _(L("Orientation found.")));
 }
 
-void Plater::priv::HollowJob::prepare()
-{
-    const GLGizmosManager& gizmo_manager = plater().q->canvas3D()->get_gizmos_manager();
-    const GLGizmoHollow* gizmo_hollow = dynamic_cast<const GLGizmoHollow*>(gizmo_manager.get_current());
-    assert(gizmo_hollow);
-    auto hlw_data = gizmo_hollow->get_hollowing_parameters();
-    m_object_mesh = hlw_data.first;
-    m_cfg = hlw_data.second;
-    m_output_mesh.reset();
-}
-
-void Plater::priv::HollowJob::process()
-{
-    sla::JobController ctl;
-    ctl.stopcondition = [this]{ return was_canceled(); };
-    ctl.statuscb = [this](unsigned st, const std::string &s) {
-        if (st < 100) update_status(int(st), s);
-    };
-    
-    std::unique_ptr<TriangleMesh> omesh =
-        sla::generate_interior(*m_object_mesh, m_cfg, ctl);
-    
-    if (omesh && !omesh->empty()) {
-        m_output_mesh.reset(new TriangleMesh{*m_object_mesh});
-        m_output_mesh->merge(*omesh);
-        m_output_mesh->require_shared_vertices();
-        
-        update_status(90, _(L("Indexing hollowed object")));
-        
-        m_output_raycaster.reset(new MeshRaycaster(*m_output_mesh));
-        
-        update_status(100, was_canceled() ? _(L("Hollowing cancelled.")) :
-                                            _(L("Hollowing done.")));
-    } else {
-        update_status(100, _(L("Hollowing failed.")));
-    }
-}
-
-void Plater::priv::HollowJob::finalize()
-{
-    if (auto gizmo = get_gizmo()) {
-        gizmo->update_mesh_raycaster(std::move(m_output_raycaster));
-        gizmo->update_hollowed_mesh(std::move(m_output_mesh));
-    }       
-}
-
-GLGizmoHollow *Plater::priv::HollowJob::get_gizmo()
-{
-    const GLGizmosManager& gizmo_manager = plater().q->canvas3D()->get_gizmos_manager();
-    auto ret = dynamic_cast<GLGizmoHollow*>(gizmo_manager.get_current());
-    assert(ret);
-    return ret;
-}
-
-const GLGizmoHollow *Plater::priv::HollowJob::get_gizmo() const
-{
-    const GLGizmosManager& gizmo_manager = plater().q->canvas3D()->get_gizmos_manager();
-    auto ret = dynamic_cast<const GLGizmoHollow*>(gizmo_manager.get_current());
-    assert(ret);
-    return ret;
-}
 
 void Plater::priv::split_object()
 {
@@ -5074,10 +4985,6 @@ void Plater::export_toolpaths_to_obj() const
     p->preview->get_canvas3d()->export_toolpaths_to_obj(into_u8(path).c_str());
 }
 
-void Plater::hollow()
-{
-    p->hollow();
-}
 
 void Plater::reslice()
 {
diff --git a/src/slic3r/GUI/Plater.hpp b/src/slic3r/GUI/Plater.hpp
index 754a2a720..f3b0181a0 100644
--- a/src/slic3r/GUI/Plater.hpp
+++ b/src/slic3r/GUI/Plater.hpp
@@ -198,7 +198,6 @@ public:
     void reload_all_from_disk();
     bool has_toolpaths_to_export() const;
     void export_toolpaths_to_obj() const;
-    void hollow();
     void reslice();
     void reslice_SLA_supports(const ModelObject &object, bool postpone_error_messages = false);
     void reslice_SLA_hollowing(const ModelObject &object, bool postpone_error_messages = false);