Best B&W Film for 35mm inter-positives

I would like to make 35 mm B&W inter-positives for making enlarged negatives for Alt processes. I would like to try Gum Printing. Tried it in college more years ago than I care to mention. I have seen the gum printing kits from the Formulary and am in the process of scaring up a suitable uv light source. I think that Ultrafine is the source for graphic arts film. I have an old but still functioning Bowens Illumitran so I can easily make copy positives. I am trying to avoid making same size graphic arts film positives then making negs for printing.

My questions are: 1) What would be the best film to use to make inter-positives and how would you develop this film? I would
like to use a film that I can purchase in bulk if at all possible.
2) Am I way off base in this way of making negatives for Alt Processing?

After well over a decade of devoting my work to 4x5 and Medium format, mostly color, I have picked up my 35mm Nikon again to explore some miniature format B&W ;-) I would like to use the images that I capture in 35 to be used for some of my Alt process work. And to think that I almost had a fire sale on all my old MF Nikon equipment.

Film that I have right now...APX 400, TMAX 400, HP5+, APX 100, Kentmere 400.
Developers that I would like to use and have on hand...XTOL, Ilford DDX and Ilfosol 3, Pyro Cat HD and MC, HC110

I am looking at two types of Inter-positives one fairly high in contrast and the other rather full in tones and lower in contrast.

I guess I am trying not to reinvent the wheel and would appreciate any advise or a good place to look on the web or in print for information on Alt Printing the analog way.

Robert, I have also been working on making enlarged negatives for alt processes. I can't answer your question about inter-positives, because I haven't done that yet. However, I've had some success with direct duplicating film. Ultrafine sells it, and also medical imaging places such as zzmedical.com (Fuji MI-DUP, which is X-ray duplicating film, Dead Link Removed). It's reasonably priced, fine-grained, and processed just like normal negative film. It's very slow: 1 - 3 minute exposures. You can use a red safelight, so as you gain experience you can develop for the needed contrast by inspection. I've made 11x14 enlarged negatives from my medium-format and 5x7 negatives that work well for Kallitypes. I have some 35mm negatives to enlarge for Kallitypes, but haven't gotten to those yet. I'd be happy to discuss it in more detail if you like - I'm in Buffalo too.

Mark

I'd skip the interpositive step and go straight to a large negative. One way, as suggested above, is to enlarge your negatives straight on positive ortho transparency material that Ultrafin sells. Another method is to enlarge your negative on standard ortho negative material and reversal process it.

..the best inter-pos film is TMAX100.

regards

I agree, tmax is tops. I sometimes make internegs from it using color slides, that is fun and easy.

I've had very good results with Plus-X, alas. I bet TMX is a good choice.

I have tried four approaches:

1. Contacting 35mm negatives in a Leitz Elida using Adox duping film (no longer made???)
2. Photographing negatives with a slide duplicator w/ TMX
3. Enlarging onto lithographic film and reversal processing as a low contrast positive (low contrast for lith film, actually was pretty high contrast)
4. Enlarging on to X-ray duplicating film

1-2) The Elida was a dust nightmare. The slide duplicator results were grainy and just didn't look right. With both these approaches I then had to 'print' the positives on to sheet film, an extra PITA (and an expensive one with the $5 - $8 / sheet price of 8x10 film).

3) Lith film worked well - no added grain, the high contrast was a plus for alt process. Processing is a bit messy with lots and lots of trays. Getting the process to work right was a bit of a challenge but once sorted was reliable.

4) X-ray duplicating film did a very good job, better than expected. Very easy to process in regular print chemistry. The best choice, IMO.

I want to try color slides enlarged on to lith film developed in LC-1.

Let me ask a question about the duplicating film.

Obviously you don't get an inter-positive. You get a direct negative as Jeffrey G has helped me understand.

Do you expose it under the enlarger with white light like paper?

what kind of exposing times?

developed to completion like paper? or to a contrast index controlled by time?

hi nicholas

is the xray duplicating film you mentioned the same stuff that photo warehouse sells ?

photo warehouse / ultrafine sells a single step contact print ( slow speed ) of dup film
that was a direct replacement for kodak's old so-132. i think it is called continuous tone duplicating film.
it makes a neg from a neg or pos - pos and processed
in print developer under a safelight. it is as slow as azo so it required both a flood light ( i used a 300watt bulb )
and a negative that isn't to be enlarged but contact printed. it is processed / developed like paper ...

or is it a different type of duplicating film that isn't single step, so you have to make an interpositive
which is then contact printed to make a negative ..

thanks !
john

The X-ray duplicating film I use comes from Ultrafine. I enlarge the negative onto the film. I can't find my notes but I don't recall the exposure times as anything out of the ordinary - a minute or two at the most. Timed development of 3 minutes [again, can't find notes but I recall it being like paper], I didn't try contrast manipulation as the results were just fine with plain-ole development in plain-ole 1:2 D-72/Dektol.