diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index f243bb3..5372a82 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -3251,7 +3251,9 @@ std::string GCodeGenerator::_extrude(
 {
     std::string gcode;
     const std::string_view description_bridge = path_attr.role.is_bridge() ? " (bridge)"sv : ""sv;
-
+    //w30
+    bool                   is_first_or_bottom_layer = (path_attr.role == ExtrusionRole::TopSolidInfill) || (this->on_first_layer());
+    bool                   is_first                 = this->on_first_layer();
     const bool has_active_instance{m_label_objects.has_active_instance()};
     if (m_writer.multiple_extruders && has_active_instance) {
         gcode += m_label_objects.maybe_change_instance(m_writer);
@@ -3332,6 +3334,13 @@ std::string GCodeGenerator::_extrude(
 
     // calculate extrusion length per distance unit
     double e_per_mm = m_writer.extruder()->e_per_mm3() * path_attr.mm3_per_mm;
+    //w30
+    if (is_first_or_bottom_layer) {
+        if (is_first)
+            e_per_mm *=  m_config.bottom_solid_infill_flow_ratio ;
+        else
+            e_per_mm *= m_config.top_solid_infill_flow_ratio ;
+    }
     if (m_writer.extrusion_axis().empty())
         // gcfNoExtrusion
         e_per_mm = 0;
diff --git a/src/libslic3r/Preset.cpp b/src/libslic3r/Preset.cpp
index 1e5ce3a..3b7059c 100644
--- a/src/libslic3r/Preset.cpp
+++ b/src/libslic3r/Preset.cpp
@@ -491,6 +491,8 @@ static std::vector<std::string> s_Preset_print_options {
     ,"precise_z_height"
     //w28
     ,"max_bridge_length"
+    //w30
+    ,"top_solid_infill_flow_ratio", "bottom_solid_infill_flow_ratio"
 };
 
 static std::vector<std::string> s_Preset_filament_options {
diff --git a/src/libslic3r/PrintConfig.cpp b/src/libslic3r/PrintConfig.cpp
index ac044d5..856ebee 100644
--- a/src/libslic3r/PrintConfig.cpp
+++ b/src/libslic3r/PrintConfig.cpp
@@ -600,6 +600,26 @@ void PrintConfigDef::init_fff_params()
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloat(1));
 
+    //w30
+    def          = this->add("top_solid_infill_flow_ratio", coFloat);
+    def->label   = L("Top surface flow ratio");
+    def->category = L("Advanced");
+    def->tooltip = L("This factor affects the amount of material for top solid infill. "
+                     "You can decrease it slightly to have smooth surface finish");
+    def->min     = 0;
+    def->max     = 2;
+    def->mode     = comAdvanced;
+    def->set_default_value(new ConfigOptionFloat(1));
+
+    def          = this->add("bottom_solid_infill_flow_ratio", coFloat);
+    def->label   = L("Bottom surface flow ratio");
+    def->category = L("Advanced");
+    def->tooltip = L("This factor affects the amount of material for bottom solid infill");
+    def->min     = 0;
+    def->max     = 2;
+    def->mode     = comAdvanced;
+    def->set_default_value(new ConfigOptionFloat(1));
+
     def = this->add("bridge_speed", coFloat);
     def->label = L("Bridges");
     def->category = L("Speed");
@@ -5064,6 +5084,12 @@ std::string validate(const FullPrintConfig &cfg)
     if (cfg.bridge_flow_ratio <= 0)
         return "Invalid value for --bridge-flow-ratio";
 
+    //w30
+    if (cfg.top_solid_infill_flow_ratio <= 0)
+        return "Invalid value for --top-solid-infill-flow-ratio";
+    if (cfg.bottom_solid_infill_flow_ratio <= 0)
+        return "Invalid value for --bottom-solid-infill-flow-ratio";
+
     // extruder clearance
     if (cfg.extruder_clearance_radius <= 0)
         return "Invalid value for --extruder-clearance-radius";
diff --git a/src/libslic3r/PrintConfig.hpp b/src/libslic3r/PrintConfig.hpp
index fe73c86..3647f64 100644
--- a/src/libslic3r/PrintConfig.hpp
+++ b/src/libslic3r/PrintConfig.hpp
@@ -668,6 +668,9 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionFloat,                top_solid_min_thickness))
     ((ConfigOptionFloatOrPercent,       top_solid_infill_speed))
     ((ConfigOptionBool,                 wipe_into_infill))
+    //w30
+    ((ConfigOptionFloat, top_solid_infill_flow_ratio))
+    ((ConfigOptionFloat, bottom_solid_infill_flow_ratio))
 )
 
 PRINT_CONFIG_CLASS_DEFINE(
diff --git a/src/slic3r/GUI/Tab.cpp b/src/slic3r/GUI/Tab.cpp
index 1ee45b7..7e5f7be 100644
--- a/src/slic3r/GUI/Tab.cpp
+++ b/src/slic3r/GUI/Tab.cpp
@@ -1681,6 +1681,9 @@ void TabPrint::build()
 
         optgroup = page->new_optgroup(L("Flow"));
         optgroup->append_single_option_line("bridge_flow_ratio");
+        //w30
+        optgroup->append_single_option_line("top_solid_infill_flow_ratio");
+        optgroup->append_single_option_line("bottom_solid_infill_flow_ratio");
 
         optgroup = page->new_optgroup(L("Slicing"));
         optgroup->append_single_option_line("slice_closing_radius");