I see. Yes contact emulsion is simpler as I said before, but the difference is like making a cup of tea with shorter steeping time with different amount of milk and sugar. You still need to boil water to the correct temperature for the leaf, and must have appropriate teapot and strainer. So the major requirement remains the same.
Contact printing emulsions don't have to be fast, so one requirement is already out of the equation. The issue is to get good contrast and low fog. In my experience, the emulsion part is easy, as long as you have good inert photographic gelatin. The difficult part is to coat it on the paper. Almost all paper stocks I tried fog silver chloride emulsion when they contact. So you have to size the paper with well hardened photographic gelatin and coat the emulsion on top of it (which is generally a good thing for improving image quality as well). Then avoid the edges of the paper and coat in areas like an inch from thee dges.
Alternatively, you can make a very slow bromide emulsion. It requires a bit more steps but the emulsion is a lot more robust against fogging.
You'll need a reacting vessel (glass, glazed earthware or titanium - no other metals, though high corrosion resistant stainless steel is also good) at temperature of 50 degrees centigrade in water jacket. This vessel has to be stirred very rapidly for an hour or so. A good mechanical stirring is a plus, but you can do it with hand for proof of concept. You also need some deionized water, photographic gelatin, silver nitrate, sodium chloride, potassium bromide, potassium iodide, sodium thiosulfate, benzotriazole, and a refrigerator (in darkroom) as a bare minimum requirement.
Anyone still willing to try? You should email me, because the whole process is more than what I'm wiling to punch into this tiny text box.
