hi chris

how dense are your 4x5 sheets and other films ?
i have found that when i contact print my sheet film ( even roll film exposures cut and contact printed )
the density of the film really makes a difference in the final print.
if the film is too thin, the optimal exposure will be short, you will need to boost contrast with
filters, or different strength developers and water baths to bathe the print in ...
and it really makes a more difficult task, not that it can't be done ...

les mclean has a great article on split grade ( filter ) printing, and i use it often when printing film on the
thin side ( thin meaning not as bullet proof as my contact printing film )
http://www.lesmcleanphotography.com/...ull&article=21

using a hard filter and a soft filter really makes muddy tones rich and crisp ..
it takes a little bit of practice but in the end the prints speak for themselves

good luck !
john