I have been using Kodak dental x-ray duplicating film for very very many years to duplicate dental x-rays (contact printed) exposed with a 15watt bulb 12 inches above the printing frame for 30seconds exposure. I have also used it to enlarge negatives for pt/pd printing. It is very slow but gives beautiful negatives. In both cases I use Kodak GBX dev. and fix which lasts approximately a month. Remember it is a reversal film so you have to do the opposite burning=less dense negative and dodging=more dense negative. It yields excellent contrast for pt/pd printing.