diff --git a/LuaLibs/AddManData.lua b/LuaLibs/AddManData.lua
index 4dc2c9c..52b6e79 100644
--- a/LuaLibs/AddManData.lua
+++ b/LuaLibs/AddManData.lua
@@ -75,6 +75,7 @@ KEY_MATERIAL = 'Material'
 KEY_LEAD_IN_TYPE = 'LeadIn'
 KEY_LEAD_IN_TANG_DIST = 'LeadInTangDist'
 KEY_LEAD_IN_ORTHO_DIST = 'LeadInOrthoDist'
+KEY_SINGLE_LEAD_IN = 'SingleLeadIn'
 KEY_LEAD_OUT_TYPE = 'LeadOut'
 KEY_LEAD_OUT_TANG_DIST= 'LeadOutTangDist'
 KEY_LEAD_OUT_ORTHO_DIST= 'LeadOutOrthoDist'
diff --git a/LuaLibs/CalcToolPath.lua b/LuaLibs/CalcToolPath.lua
index a761c42..0788139 100644
--- a/LuaLibs/CalcToolPath.lua
+++ b/LuaLibs/CalcToolPath.lua
@@ -37,6 +37,7 @@ local function GetLayerParamsForToolPathCalc()
    LayerParams.nLinkType = EgtGetInfo( s_nPartId, KEY_LINK_TYPE, 'i')
    LayerParams.dLinkParam = EgtGetInfo( s_nPartId, KEY_LINK_PARAM, 'd')
    LayerParams.nLeadInType = EgtGetInfo( s_nPartId, KEY_LEAD_IN_TYPE, 'i')
+   LayerParams.bSingleLeadIn = EgtGetInfo( s_nPartId, KEY_SINGLE_LEAD_IN, 'b') or true
    LayerParams.dLeadInTangDist = EgtGetInfo( s_nPartId, KEY_LEAD_IN_TANG_DIST, 'd')
    LayerParams.dLeadInOrthoDist = EgtGetInfo( s_nPartId, KEY_LEAD_IN_ORTHO_DIST, 'd')
    LayerParams.nLeadOutType = EgtGetInfo( s_nPartId, KEY_LEAD_OUT_TYPE, 'i')
@@ -65,7 +66,7 @@ local function GetLayerParamsForToolPathCalc()
    -- parametri da file ini del programma
    local sIniFile = EgtGetIniFile()
    LayerParams.dSpiralVaseInterpLen = EgtGetNumberFromIni( '3dPrinting', KEY_SPIRAL_VASE_INTERP_LEN, 100.0, sIniFile)
-   
+
    return LayerParams
 end
 
@@ -610,7 +611,7 @@ local function AddRetractionOnLastCrv( nCrvId, nTpathGrpId, LayerParams, dCoasti
 end
 
 ---------------------------------------------------------------------
-local function CalcShellsToolPath( vEntIds, nTpathGrpId, LayerParams)
+local function CalcShellsToolPath( vEntIds, nTpathGrpId, bFirst, LayerParams)
    
    if not vEntIds or #vEntIds == 0 then return end
    
@@ -638,7 +639,9 @@ local function CalcShellsToolPath( vEntIds, nTpathGrpId, LayerParams)
    
    -- aggiungo leadin/leadout
    if LayerParams.nLeadInType ~= LEAD_TYPE.NONE then
-      AddLeadIn( vIds[1], LayerParams, nTpathGrpId)
+      if bFirst or not LayerParams.bSingleLeadIn then
+         AddLeadIn( vIds[1], LayerParams, nTpathGrpId)
+      end
    end
    if LayerParams.nLeadOutType ~= LEAD_TYPE.NONE then
       EgtTrimCurveEndAtLen( vIds[#vIds], EgtCurveLength( vIds[#vIds]) - LayerParams.dOffsetLP)
@@ -3013,6 +3016,7 @@ function CalcToolPath.Exec( nPartId)
    -- recupero i parametri per calcolo dei toolpath
    local LayerParams = GetLayerParamsForToolPathCalc()
    local nSlicingType = EgtGetInfo( s_nPartId, KEY_SLICING_TYPE, 'i')
+   local nFirstSolidLay = EgtGetInfo( s_nPartId, KEY_FIRST_SOLID_LAY, 'i')
    
    -- caso spiral vase
    if LayerParams.bSpiralVase then
@@ -3073,7 +3077,7 @@ function CalcToolPath.Exec( nPartId)
 
             -- shell
             if LayerParams.vPrintOrder[j] == PRINT_ELEMENT.SHELL then
-               CalcShellsToolPath( vShellIds, nTpathGrpId, LayerParams)
+               CalcShellsToolPath( vShellIds, nTpathGrpId, nIdx == nFirstSolidLay, LayerParams)
             
             -- extra shell
             elseif LayerParams.vPrintOrder[j] == PRINT_ELEMENT.EXTRA_SHELL then