Thanks wyrwulf and Clint ! I did read Bushi's Tutorial before and his method of slicing a model in the MFM does not work for me. I guess he is using another version of RDS because there is no menu item "Naming Polygons" in my selection menu. I must state that I am using a german version, so the name itself might be different. But I tried all reasonable menu items after selecting the vertices, but not one worked the way Bushi is describing in his tutorial. The same naming problem occurs with your tip also, Clint. Please could you tell me wich version of RDS are you using, to check if an upgrade solves my problem. Thank you again ! Arthur.