I don't have a DUAL (not duel) extruder yet. But, I wanted to print the filling - then two cookies and sandwich them. So, I stripped the bottom cookie from the cookie from the "Duel" color version. (Would it not be names Thingeo not Thingio? it is similar to an Oreo (note the "eo" not "io" in its name... meh guess I am being critical after seeing "duel" where dual is needed and "then" instead of than so often).