diff --git a/src/Mod/Arch/importOBJ.py b/src/Mod/Arch/importOBJ.py
index 2283312bcb..4e35459beb 100644
--- a/src/Mod/Arch/importOBJ.py
+++ b/src/Mod/Arch/importOBJ.py
@@ -247,7 +247,7 @@ def export(exportList,filename,colors=None):
         outfile = pythonopen(filenamemtl,"w")
         outfile.write("# FreeCAD v" + ver[0] + "." + ver[1] + " build" + ver[2] + " Arch module\n")
         outfile.write("# https://www.freecadweb.org\n")
-        kinds = {"AmbientColor":"Ka ","DiffuseColor":"Kd ","SpecularColor":"Ks ","EmissiveColor":"Ke ","Transparency":"Tr "}
+        kinds = {"AmbientColor":"Ka ","DiffuseColor":"Kd ","SpecularColor":"Ks ","EmissiveColor":"Ke ","Transparency":"Tr ","Dissolve":"d "}
         done = [] # store names to avoid duplicates
         for mat in materials:
             if isinstance(mat,tuple):
@@ -255,6 +255,7 @@ def export(exportList,filename,colors=None):
                     outfile.write("newmtl " + mat[0] + "\n")
                     outfile.write("Kd " + str(mat[1][0]) + " " + str(mat[1][1]) + " " + str(mat[1][2]) + "\n")
                     outfile.write("Tr " + str(mat[2]/100) + "\n")
+                    outfile.write("d " + str(1-mat[2]/100) + "\n")
                     done.append(mat[0])
             else:
                 if not mat.Name in done:
@@ -337,7 +338,7 @@ def insert(filename,docname):
                         elif mline[:3] == "Kd ":
                             color = tuple([float(i) for i in mline[3:].split()])
                         elif mline[:2] == "d ":
-                            trans = int(float(mline[2:])*100)
+                            trans = int((1-float(mline[2:]))*100)
                     if mname and color:
                         colortable[mname] = [color,trans]
         elif line[:2] == "o ":