Is it possible to make your own filters? Of course it would be hard to make something that has even remotely comparable optical qualities of the commercially available counterpart, but I simply can't afford to by a dozen 4" wratten filters to experiment with. I mainly want colours for adjusting b&w film.

A few ideas:

*Ask a print shop to print colour on transparencies?
*Dye a gelatin solution and mold poor-mans wrattens?
*Paint some thin transparent plastic with a clear paint?

Any more sane ideas? Anybody tried a method that worked? Compensation factors would have to be estimated with an exposure meter or something, that's a minor problem.

It would be fun to hear anybody elses experience.