Hey Michael, MANY MANY THX!!! THAT was it!! BOA ... - you made my day :-) - I fully agree, I couldn't select them all and press the network button - there was an error every time. So I decided to do it in small steps (surface to surface). How do you managed this :-)? The only difference I see is that you connected all curves and have just 1 curve separated so that it is not a closed one - is that true? Again, many THX (also for the links - I will study them immediately :-))!!