diff --git a/resources/ui_layout/Readme.md b/resources/ui_layout/Readme.md
index ce59794a5..16556604a 100644
--- a/resources/ui_layout/Readme.md
+++ b/resources/ui_layout/Readme.md
@@ -41,6 +41,7 @@ each parameter is separated by ':'
 	* STR, the last parameter: the id name of the setting.
 	* label$STR: to override the label by this new one (if it ends with '_' it won't have a ':' ; if empty it won't have a length).
 	* label_width$INT: change the width of the label. Only works if it's in a line. Override the group one. -1 for auto.
+	* full_label$STR: to override the full_label by this new one (full_label is used on modifiers).
 	* full_label: to override the label by the "full one".
 	* full_width: to tell to create a field that span the full width.
 	* sidetext$STR: the suffix at the right of the widget (like 'mm').
@@ -48,6 +49,7 @@ each parameter is separated by ':'
 	* simple|advanced|expert: add one of these to modify the mode in which this setting appear.
 	* width$INT: change the width of the field. Shouod work on most type of settings.
 	* height$INT: change the height of the field. Don't works with every type of setting.
+	* precision$INT: number of digit after the dot displayed.
 	* url$STR: the url to call when clicking on it.
 	* id $INT: for setting only a single value of a setting array.
 	* idx: for setting only a single value of a setting array, with the index of the page (for extruder ui page)
diff --git a/src/libslic3r/Config.hpp b/src/libslic3r/Config.hpp
index 35010af25..058bebeb6 100644
--- a/src/libslic3r/Config.hpp
+++ b/src/libslic3r/Config.hpp
@@ -1696,6 +1696,8 @@ public:
     // By setting min=0, only nonnegative input is allowed.
     double                              min = INT_MIN;
     double                              max = INT_MAX;
+    // max precision after the dot, only for display
+    int                                 precision = 6;
     ConfigOptionMode                    mode = comSimple;
     // Legacy names for this configuration option.
     // Used when parsing legacy configuration file.
diff --git a/src/libslic3r/PrintConfig.cpp b/src/libslic3r/PrintConfig.cpp
index 567bc7435..a9559f49d 100644
--- a/src/libslic3r/PrintConfig.cpp
+++ b/src/libslic3r/PrintConfig.cpp
@@ -136,6 +136,7 @@ void PrintConfigDef::init_common_params()
                      "The gap closing operation may reduce the final print resolution, therefore it is advisable to keep the value reasonably low.");
     def->sidetext = L("mm");
     def->min = 0;
+    def->precision = 8;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloat(0.049));
 
@@ -835,6 +836,8 @@ void PrintConfigDef::init_fff_params()
     def->sidetext = L("mm or %");
     def->ratio_over = "nozzle_diameter";
     def->min = 0;
+    def->max = 1000;
+    def->precision = 6;
     def->can_phony = true;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false));
@@ -849,6 +852,8 @@ void PrintConfigDef::init_fff_params()
     def->sidetext = L("mm or %");
     def->ratio_over = "nozzle_diameter";
     def->min = 0;
+    def->max = 1000;
+    def->precision = 6;
     def->can_phony = true;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false, true));
@@ -1168,6 +1173,7 @@ void PrintConfigDef::init_fff_params()
     def->ratio_over = "nozzle_diameter";
     def->min = 0;
     def->max = 1000;
+    def->precision = 6;
     def->can_phony = true;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false));
@@ -1181,6 +1187,7 @@ void PrintConfigDef::init_fff_params()
     def->ratio_over = "nozzle_diameter";
     def->min = 0;
     def->max = 1000;
+    def->precision = 6;
     def->can_phony = true;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false, true));
@@ -1753,6 +1760,7 @@ void PrintConfigDef::init_fff_params()
     def->ratio_over = "nozzle_diameter";
     def->min = 0;
     def->max = 1000;
+    def->precision = 6;
     def->can_phony = true;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(140, true));
@@ -1767,6 +1775,7 @@ void PrintConfigDef::init_fff_params()
     def->ratio_over = "nozzle_diameter";
     def->min = 0;
     def->max = 1000;
+    def->precision = 6;
     def->can_phony = true;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false, true));
@@ -2149,6 +2158,7 @@ void PrintConfigDef::init_fff_params()
     def->ratio_over = "nozzle_diameter";
     def->min = 0;
     def->max = 1000;
+    def->precision = 6;
     def->can_phony = true;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false));
@@ -2163,6 +2173,7 @@ void PrintConfigDef::init_fff_params()
     def->ratio_over = "nozzle_diameter";
     def->min = 0;
     def->max = 1000;
+    def->precision = 6;
     def->can_phony = true;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false, true));
@@ -2624,6 +2635,7 @@ void PrintConfigDef::init_fff_params()
                      "\n0 to disable.");
     def->sidetext = L("mm");
     def->min = 0;
+    def->precision = 8;
     def->mode = comExpert;
     def->set_default_value(new ConfigOptionFloat(0.035));
 
@@ -2888,6 +2900,7 @@ void PrintConfigDef::init_fff_params()
     def->aliases = { "perimeters_extrusion_width" };
     def->min = 0;
     def->max = 1000;
+    def->precision = 6;
     def->can_phony = true;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false));
@@ -2902,6 +2915,7 @@ void PrintConfigDef::init_fff_params()
     def->aliases = { "perimeters_extrusion_width" };
     def->min = 0;
     def->max = 1000;
+    def->precision = 6;
     def->can_phony = true;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false, true));
@@ -3013,6 +3027,7 @@ void PrintConfigDef::init_fff_params()
         "\nInfill & Thin areas are simplified up to 0.0125mm.");
     def->sidetext = L("mm");
     def->min = 0;
+    def->precision = 8;
     def->mode = comExpert;
     def->set_default_value(new ConfigOptionFloat(0.002));
 
@@ -3244,9 +3259,10 @@ void PrintConfigDef::init_fff_params()
     def->tooltip = L("Horizontal width of the skirt that will be printed around each object."
         " If left zero, first layer extrusion width will be used if set and the skirt is only 1 layer height"
         ", or perimeter extrusion width will be used (using the computed value if not set).");
-    def->sidetext = L("mm");
+    def->sidetext = L("mm or %");
     def->min = 0;
     def->max = 1000;
+    def->precision = 6;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false));
 
@@ -3359,6 +3375,7 @@ void PrintConfigDef::init_fff_params()
         "\nIt's really only useful to smoothen functional models or very wide angles.");
     def->sidetext = L("mm");
     def->min = 0;
+    def->precision = 8;
     def->cli = "curve-smoothing-precision=f";
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloat(0));
@@ -3415,6 +3432,7 @@ void PrintConfigDef::init_fff_params()
     def->ratio_over = "nozzle_diameter";
     def->min = 0;
     def->max = 1000;
+    def->precision = 6;
     def->can_phony = true;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false));
@@ -3429,6 +3447,7 @@ void PrintConfigDef::init_fff_params()
     def->ratio_over = "nozzle_diameter";
     def->min = 0;
     def->max = 1000;
+    def->precision = 6;
     def->can_phony = true;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false, true));
@@ -3535,6 +3554,7 @@ void PrintConfigDef::init_fff_params()
         " Put 0 to disable.");
     def->sidetext = L("mm");
     def->min = 0;
+    def->precision = 8;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloat(0.0001));
 
@@ -3710,6 +3730,7 @@ void PrintConfigDef::init_fff_params()
     def->ratio_over = "nozzle_diameter";
     def->min = 0;
     def->max = 1000;
+    def->precision = 6;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false));
 
@@ -3994,6 +4015,7 @@ void PrintConfigDef::init_fff_params()
     def->ratio_over = "nozzle_diameter";
     def->min = 0;
     def->max = 1000;
+    def->precision = 6;
     def->can_phony = true;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false));
@@ -4007,6 +4029,7 @@ void PrintConfigDef::init_fff_params()
     def->ratio_over = "nozzle_diameter";
     def->min = 0;
     def->max = 1000;
+    def->precision = 6;
     def->can_phony = true;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(0, false, true));
@@ -4348,6 +4371,7 @@ void PrintConfigDef::init_fff_params()
     def->cli = "z-step=f";
     def->sidetext = L("mm");
     def->min = 0;
+    def->precision = 8;
     def->mode = comExpert;
     def->set_default_value(new ConfigOptionFloat(0.005));
 
@@ -5840,6 +5864,7 @@ bool DynamicPrintConfig::update_phony(const std::vector<const DynamicPrintConfig
     return something_changed;
 }
 
+//note: width<-> spacing conversion is done via float, so max 6-7 digit of precision.
 bool DynamicPrintConfig::value_changed(const t_config_option_key& opt_key, const std::vector<const DynamicPrintConfig*> config_collection) {
 
     if (opt_key == "layer_height") {
diff --git a/src/slic3r/GUI/Field.cpp b/src/slic3r/GUI/Field.cpp
index d5619d465..e54519c70 100644
--- a/src/slic3r/GUI/Field.cpp
+++ b/src/slic3r/GUI/Field.cpp
@@ -26,7 +26,7 @@
 
 namespace Slic3r { namespace GUI {
 
-wxString double_to_string(double const value, const int max_precision /*= 8*/)
+wxString double_to_string(double const value, const int max_precision /*= 6*/)
 {
 // Style_NoTrailingZeroes does not work on OSX. It also does not work correctly with some locales on Windows.
 //	return wxNumberFormatter::ToString(value, max_precision, wxNumberFormatter::Style_NoTrailingZeroes);
@@ -240,7 +240,7 @@ void Field::get_value_by_opt_type(wxString& str, const bool check_value/* = true
 
 			wxString label = m_opt.full_label.empty() ? _(m_opt.label) : _(m_opt.full_label);
             show_error(m_parent, from_u8((boost::format(_utf8(L("%s doesn't support percentage"))) % label).str()));
-			set_value(double_to_string(m_opt.min), true);
+			set_value(double_to_string(m_opt.min, m_opt.precision), true);
 			m_value = double(m_opt.min);
 			break;
 		}
@@ -260,7 +260,7 @@ void Field::get_value_by_opt_type(wxString& str, const bool check_value/* = true
                     break;
                 }
                 show_error(m_parent, _(L("Invalid numeric input.")));
-                set_value(double_to_string(val), true);
+                set_value(double_to_string(val, m_opt.precision), true);
             }
             if (m_opt.min > val || val > m_opt.max)
             {
@@ -280,7 +280,7 @@ void Field::get_value_by_opt_type(wxString& str, const bool check_value/* = true
                             }
                             else
                                 val = boost::any_cast<double>(m_value);
-                            set_value(double_to_string(val), true);
+                            set_value(double_to_string(val, m_opt.precision), true);
                         }
                     }
                 }
@@ -288,7 +288,7 @@ void Field::get_value_by_opt_type(wxString& str, const bool check_value/* = true
                     show_error(m_parent, _L("Input value is out of range"));
                     if (m_opt.min > val) val = m_opt.min;
                     if (val > m_opt.max) val = m_opt.max;
-                    set_value(double_to_string(val), true);
+                    set_value(double_to_string(val, m_opt.precision), true);
                 }
             }
         }
@@ -314,7 +314,7 @@ void Field::get_value_by_opt_type(wxString& str, const bool check_value/* = true
                     break;
                 }
                 show_error(m_parent, _(L("Invalid numeric input.")));
-                set_value(double_to_string(val), true);
+                set_value(double_to_string(val, m_opt.precision), true);
             } else {
 
                 //at least check min, as we can want a 0 min
@@ -326,7 +326,7 @@ void Field::get_value_by_opt_type(wxString& str, const bool check_value/* = true
                     }
                     show_error(m_parent, _(L("Input value is out of range")));
                     if (m_opt.min > val) val = m_opt.min;
-                    set_value(double_to_string(val), true);
+                    set_value(double_to_string(val, m_opt.precision), true);
                 } else if (((m_opt.sidetext.rfind("mm/s") != std::string::npos && val > m_opt.max) ||
                      (m_opt.sidetext.rfind("mm ") != std::string::npos && val > 1)) &&
                      (m_value.empty() || std::string(str.ToUTF8().data()) != boost::any_cast<std::string>(m_value)))
@@ -356,7 +356,7 @@ void Field::get_value_by_opt_type(wxString& str, const bool check_value/* = true
                     bool infill_anchors = m_opt.opt_key == "infill_anchor" || m_opt.opt_key == "infill_anchor_max";
 
                     const std::string sidetext = m_opt.sidetext.rfind("mm/s") != std::string::npos ? "mm/s" : "mm";
-                    const wxString stVal = double_to_string(val, 2);
+                    const wxString stVal = double_to_string(val, m_opt.precision);
                     const wxString msg_text = from_u8((boost::format(_utf8(L("Do you mean %s%% instead of %s %s?\n"
                         "Select YES if you want to change this value to %s%%, \n"
                         "or NO if you are sure that %s %s is a correct value."))) % stVal % stVal % sidetext % stVal % stVal % sidetext).str());
@@ -456,14 +456,14 @@ void TextCtrl::BUILD() {
 	switch (m_opt.type) {
 	case coFloatOrPercent:
 	{
-		text_value = double_to_string(m_opt.default_value->getFloat());
+		text_value = double_to_string(m_opt.default_value->getFloat(), m_opt.precision);
 		if (m_opt.get_default_value<ConfigOptionFloatOrPercent>()->percent)
 			text_value += "%";
 		break;
 	}
 	case coPercent:
 	{
-		text_value = double_to_string(m_opt.default_value->getFloat());
+		text_value = double_to_string(m_opt.default_value->getFloat(), m_opt.precision);
 		text_value += "%";
 		break;
 	}	
@@ -476,7 +476,7 @@ void TextCtrl::BUILD() {
 			m_opt.type == coFloat ? 
 				m_opt.default_value->getFloat() :
 				m_opt.get_default_value<ConfigOptionPercents>()->get_at(m_opt_idx);
-		text_value = double_to_string(val);
+		text_value = double_to_string(val, m_opt.precision);
         m_last_meaningful_value = text_value;
 		break;
 	}
@@ -1082,7 +1082,7 @@ void Choice::set_selection()
 		break;
 	}
 	case coFloatOrPercent: {
-		text_value = double_to_string(m_opt.default_value->getFloat());
+		text_value = double_to_string(m_opt.default_value->getFloat(), m_opt.precision);
 		if (m_opt.get_default_value<ConfigOptionFloatOrPercent>()->percent)
 			text_value += "%";
 		break;
diff --git a/src/slic3r/GUI/Field.hpp b/src/slic3r/GUI/Field.hpp
index 42aaa5372..bd38dc649 100644
--- a/src/slic3r/GUI/Field.hpp
+++ b/src/slic3r/GUI/Field.hpp
@@ -36,7 +36,7 @@ using t_kill_focus = std::function<void(const std::string&)>;
 using t_change = std::function<void(const t_config_option_key&, const boost::any&)>;
 using t_back_to_init = std::function<void(const std::string&)>;
 
-wxString double_to_string(double const value, const int max_precision = 8);
+wxString double_to_string(double const value, const int max_precision = 6);
 wxString get_points_string(const std::vector<Vec2d>& values);
 
 class Field {
diff --git a/src/slic3r/GUI/OptionsGroup.cpp b/src/slic3r/GUI/OptionsGroup.cpp
index 3740d7bf3..a9e3449d4 100644
--- a/src/slic3r/GUI/OptionsGroup.cpp
+++ b/src/slic3r/GUI/OptionsGroup.cpp
@@ -857,7 +857,7 @@ boost::any ConfigOptionsGroup::get_config_value(const DynamicPrintConfig& config
                 double val = opt->type == coFloats ?
                             config.option<ConfigOptionFloatsNullable>(opt_key)->get_at(idx) :
                             config.option<ConfigOptionPercentsNullable>(opt_key)->get_at(idx);
-                ret = double_to_string(val); }
+                ret = double_to_string(val, opt->precision); }
             }
             break;
         case coBools:
@@ -877,7 +877,7 @@ boost::any ConfigOptionsGroup::get_config_value(const DynamicPrintConfig& config
 	case coFloatOrPercent:{
 		const auto &value = *config.option<ConfigOptionFloatOrPercent>(opt_key);
 
-        text_value = double_to_string(value.value);
+        text_value = double_to_string(value.value, opt->precision);
 		if (value.percent)
 			text_value += "%";
 
@@ -886,7 +886,7 @@ boost::any ConfigOptionsGroup::get_config_value(const DynamicPrintConfig& config
 	}
 	case coPercent:{
 		double val = config.option<ConfigOptionPercent>(opt_key)->value;
-        text_value = double_to_string(val);
+        text_value = double_to_string(val, opt->precision);
 		ret = text_value;
 	}
 		break;
@@ -897,7 +897,7 @@ boost::any ConfigOptionsGroup::get_config_value(const DynamicPrintConfig& config
 					config.opt_float(opt_key, idx) :
 						opt->type == coFloat ? config.opt_float(opt_key) :
 						config.option<ConfigOptionPercents>(opt_key)->get_at(idx);
-		ret = double_to_string(val);
+		ret = double_to_string(val, opt->precision);
 		}
 		break;
 	case coString:
diff --git a/src/slic3r/GUI/Tab.cpp b/src/slic3r/GUI/Tab.cpp
index 8daeacde0..d8f5fb359 100644
--- a/src/slic3r/GUI/Tab.cpp
+++ b/src/slic3r/GUI/Tab.cpp
@@ -1798,7 +1798,7 @@ bool Tab::create_pages(std::string setting_type_name, int idx_page)
                     option.opt.label = option.opt.full_label;
                     need_to_notified_search = true;
                 }
-                else if (params[i].find("label$") != std::string::npos)
+                else if (boost::starts_with(params[i], "label$"))
                 {
                     option.opt.label = L(params[i].substr(6, params[i].size() - 6));
                     need_to_notified_search = true;
@@ -1806,11 +1806,11 @@ bool Tab::create_pages(std::string setting_type_name, int idx_page)
                 else if (boost::starts_with(params[i], "label_width$")) {
                     option.opt.label_width = atoi(params[i].substr(12, params[i].size() - 12).c_str());
                 }
-                else if (params[i].find("sidetext$") != std::string::npos)
+                else if (boost::starts_with(params[i], "sidetext$"))
                 {
                     option.opt.sidetext = L(params[i].substr(9, params[i].size() - 9));
                 }
-                else if (params[i].find("sidetext_width$") != std::string::npos)
+                else if (boost::starts_with(params[i], "sidetext_width$"))
                 {
                     option.opt.sidetext_width = atoi(params[i].substr(15, params[i].size() - 15).c_str());
                 }
@@ -1823,13 +1823,16 @@ bool Tab::create_pages(std::string setting_type_name, int idx_page)
                 else if (boost::starts_with(params[i], "height$")) {
                     option.opt.height = atoi(params[i].substr(7, params[i].size() - 7).c_str());
                 }
+                else if (boost::starts_with(params[i], "precision$")) {
+                    option.opt.precision = atoi(params[i].substr(7, params[i].size() - 7).c_str());
+                }
                 else if (params[i] == "color") {
                     colored = true;
                 }
                 else if (boost::starts_with(params[i], "url$")) { // only on line
                     label_path = params[i].substr(4, params[i].size() - 4);
                 }
-                else if (params[i].find("tooltip$") != std::string::npos)
+                else if (boost::starts_with(params[i], "tooltip$"))
                 {
                     option.opt.tooltip = L(params[i].substr(8, params[i].size() - 8));
                     need_to_notified_search = true;
diff --git a/src/slic3r/GUI/UnsavedChangesDialog.cpp b/src/slic3r/GUI/UnsavedChangesDialog.cpp
index c11e0279e..fa1e09d6f 100644
--- a/src/slic3r/GUI/UnsavedChangesDialog.cpp
+++ b/src/slic3r/GUI/UnsavedChangesDialog.cpp
@@ -911,12 +911,12 @@ static wxString get_string_value(std::string opt_key, const DynamicPrintConfig&
         return from_u8((boost::format("%1%%%") % int(val)).str());
     }
     case coFloat:
-        return double_to_string(config.opt_float(opt_key));
+        return double_to_string(config.opt_float(opt_key), opt->precision);
     case coFloats: {
         double val = is_nullable ?
             config.opt<ConfigOptionFloatsNullable>(opt_key)->get_at(opt_idx) :
             config.opt<ConfigOptionFloats>(opt_key)->get_at(opt_idx);
-        return double_to_string(val);
+        return double_to_string(val, opt->precision);
     }
     case coString:
         return from_u8(config.opt_string(opt_key));
@@ -937,9 +937,9 @@ static wxString get_string_value(std::string opt_key, const DynamicPrintConfig&
         break;
         }
     case coFloatOrPercent: {
-        const ConfigOptionFloatOrPercent* opt = config.opt<ConfigOptionFloatOrPercent>(opt_key);
-        if (opt)
-            out = double_to_string(opt->value) + (opt->percent ? "%" : "");
+        const ConfigOptionFloatOrPercent* float_percent = config.opt<ConfigOptionFloatOrPercent>(opt_key);
+        if (float_percent)
+            out = double_to_string(float_percent->value, opt->precision) + (float_percent->percent ? "%" : "");
         return out;
     }
     case coEnum: {