I missed the part about the OP wanting to do contact prints, I am just addressing making negs from slides for enlargement.

Well Ian my labs did both ways , the easier way is to enlarge to a 4x5 sheet, the harder way is to contact, but IMHO and those of our clients were the contact internegs were vastly superior. one less optical projection if you want to think about that.
Making contact internegs is a pain for dust control and we had lots of little tricks for that. Worth the effort.

Now I still hope you send me those fix formulas , and when I get over there I am still welcome for a spot of tea eh.

Quote Originally Posted by Ian Grant View Post
My lab (unfortunately long closed) used to make all it's internegs by enlargement on to sheet film, however they had the best copying set up available, essentially a De Vere 5x4 head used as a light source with a copy camera above it. You do see these for sale sometimes.

I have to disagree with Bob here as this gave the highest possible quality internegs, it was also used to make 5x4 transparencies from 35mm Kodachromes etc.