Best way to get Kodalith-like results?

I need to create some Kodalith-like 35mm negatives for a project that I'm working on. I am shooting black and white printed material and have used Rollei Ortho 25 previously. While the contrast is very good, the white areas are not clear. I'd like to get the look of Kodalith, where black is black and white is clear.

Can Rollei Ortho 25 be processed in a way to mimic Kodalith?

I know that I can get some really old Kodalith spooled into 35mm canisters. I'm not as concerned about the age of the film as I am finding a place to process the film using the kodalith developer. I don't process my own film... I'd rather pay to have it done.

Any suggestions?

Use a lith developer. These are simple formulations, usually consisting only of Hydroquinone, caustic soda and Potassium Bromide.

I doubt you'll find any commercial lab that'll make up lith developer as a one-off. Not at any sensible price.

However, the exposure is critical with lith work, so you'll need to experiment a lot with different exposures and development times to get the exact effect you're after.

Lith film is usually developed by inspection, but times are short. Usually no longer than 3.5 minutes. Any longer and you risk the emulsion floating off the base!

This is one of Ilford's old Lith formulae:

It's divided into 2 parts for a better shelf life. Single part lith developers have to be made up and used within 30 minutes or so.

If you make it up as a single solution just before use, you can drop the metabisulphite and lower the Sodium Hydroxide to 30gms.

Even using the above developer, you'll probably still get some shades of grey on normal film. There's really no substitute for Kodalith or a similar emulsion.