diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index 5755c3b..e27aa3e 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -2862,7 +2862,8 @@ std::string GCodeGenerator::extrude_loop(const ExtrusionLoop &loop_src, const GC
     // if polyline was shorter than the clipping distance we'd get a null polyline, so
     // we discard it in that case.
     if (m_enable_loop_clipping)
-        clip_end(smooth_path, scaled<double>(EXTRUDER_CONFIG(nozzle_diameter)) * LOOP_CLIPPING_LENGTH_OVER_NOZZLE_DIAMETER, scaled<double>(min_gcode_segment_length));
+    //Y21
+        clip_end(smooth_path, scaled<double>(EXTRUDER_CONFIG(nozzle_diameter)) * (m_config.seam_gap.value / 100), scaled<double>(min_gcode_segment_length));
 
     if (smooth_path.empty())
         return {};
diff --git a/src/libslic3r/Preset.cpp b/src/libslic3r/Preset.cpp
index de6c963..65c8e33 100644
--- a/src/libslic3r/Preset.cpp
+++ b/src/libslic3r/Preset.cpp
@@ -473,6 +473,8 @@ static std::vector<std::string> s_Preset_print_options {
     ,"first_layer_infill_speed"
     //w11
     ,"detect_narrow_internal_solid_infill"
+    //Y21
+    ,"seam_gap"
 };
 
 static std::vector<std::string> s_Preset_filament_options {
diff --git a/src/libslic3r/Print.cpp b/src/libslic3r/Print.cpp
index 7d4412c..c7677e7 100644
--- a/src/libslic3r/Print.cpp
+++ b/src/libslic3r/Print.cpp
@@ -142,6 +142,8 @@ bool Print::invalidate_state_by_config_options(const ConfigOptionResolver & /* n
         "retract_restart_extra",
         "retract_restart_extra_toolchange",
         "retract_speed",
+        //Y21
+        "seam_gap",
         "single_extruder_multi_material_priming",
         "slowdown_below_layer_time",
         "solid_infill_acceleration",
diff --git a/src/libslic3r/PrintConfig.cpp b/src/libslic3r/PrintConfig.cpp
index 5476d55..54732a3 100644
--- a/src/libslic3r/PrintConfig.cpp
+++ b/src/libslic3r/PrintConfig.cpp
@@ -2533,6 +2533,15 @@ void PrintConfigDef::init_fff_params()
     def->mode = comSimple;
     def->set_default_value(new ConfigOptionEnum<SeamPosition>(spAligned));
 
+//Y21
+    def = this->add("seam_gap", coPercent);
+    def->label = L("Seam gap");
+    def->tooltip = L("In order to reduce the visibility of the seam in a closed loop extrusion, the loop is interrupted and shortened by a specified amount.\n" "This amount as a percentage of the current extruder diameter. The default value for this parameter is 15");
+    def->sidetext = L("%");
+    def->min = 0;
+    def->mode = comExpert;
+    def->set_default_value(new ConfigOptionPercent(15));
+
     def = this->add("staggered_inner_seams", coBool);
     def->label = L("Staggered inner seams");
     // TRN PrintSettings: "Staggered inner seams"
diff --git a/src/libslic3r/PrintConfig.hpp b/src/libslic3r/PrintConfig.hpp
index 2499721..3c6b6ab 100644
--- a/src/libslic3r/PrintConfig.hpp
+++ b/src/libslic3r/PrintConfig.hpp
@@ -524,6 +524,8 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionFloat,               raft_first_layer_expansion))
     ((ConfigOptionInt,                 raft_layers))
     ((ConfigOptionEnum<SeamPosition>,  seam_position))
+    //Y21
+    ((ConfigOptionPercent,            seam_gap))
     ((ConfigOptionBool,                staggered_inner_seams))
 //  ((ConfigOptionFloat,               seam_preferred_direction))
 //  ((ConfigOptionFloat,               seam_preferred_direction_jitter))
diff --git a/src/libslic3r/PrintObject.cpp b/src/libslic3r/PrintObject.cpp
index 8732483..48c9dcc 100644
--- a/src/libslic3r/PrintObject.cpp
+++ b/src/libslic3r/PrintObject.cpp
@@ -868,6 +868,8 @@ bool PrintObject::invalidate_state_by_config_options(
             steps.emplace_back(posSlice);
         } else if (
                opt_key == "seam_position"
+            //Y21
+            || opt_key == "seam_gap"
             || opt_key == "seam_preferred_direction"
             || opt_key == "seam_preferred_direction_jitter"
             || opt_key == "support_material_speed"
diff --git a/src/slic3r/GUI/ConfigManipulation.cpp b/src/slic3r/GUI/ConfigManipulation.cpp
index 5219666..4b42350 100644
--- a/src/slic3r/GUI/ConfigManipulation.cpp
+++ b/src/slic3r/GUI/ConfigManipulation.cpp
@@ -244,7 +244,8 @@ void ConfigManipulation::toggle_print_fff_options(DynamicPrintConfig* config)
 {
     bool have_perimeters = config->opt_int("perimeters") > 0;
     for (auto el : { "extra_perimeters","extra_perimeters_on_overhangs", "thin_walls", "overhangs",
-                    "seam_position","staggered_inner_seams", "external_perimeters_first", "external_perimeter_extrusion_width",
+//Y21
+                    "seam_position","seam_gap","staggered_inner_seams", "external_perimeters_first", "external_perimeter_extrusion_width",
                     "perimeter_speed", "small_perimeter_speed", "external_perimeter_speed", "enable_dynamic_overhang_speeds"})
         toggle_field(el, have_perimeters);
 
diff --git a/src/slic3r/GUI/Tab.cpp b/src/slic3r/GUI/Tab.cpp
index 005e036..0636386 100644
--- a/src/slic3r/GUI/Tab.cpp
+++ b/src/slic3r/GUI/Tab.cpp
@@ -1461,6 +1461,8 @@ void TabPrint::build()
 
         optgroup = page->new_optgroup(L("Advanced"));
         optgroup->append_single_option_line("seam_position", category_path + "seam-position");
+        //Y21
+        optgroup->append_single_option_line("seam_gap", category_path + "seam-gap");
         optgroup->append_single_option_line("staggered_inner_seams", category_path + "staggered-inner-seams");
         optgroup->append_single_option_line("external_perimeters_first", category_path + "external-perimeters-first");
         optgroup->append_single_option_line("gap_fill_enabled", category_path + "fill-gaps");