Hi. Having tested the alternatives and the fussiness of them, I wanted a slower-acting matrice developer which I could potentially use in drums and that was easy to mix. I settled on a tweak of HC-110 with post hardening. No dichromate involved. A few minutes slower than tanning developer but much simpler and seems to give comparable results when printing. I happen to be using the newer Efke matrix film, but the older Kodak film should work similarly. Dyes are no problem. I have Kodak dyes as well as a set of Pylam dyes. There are also a variety of mordants which can be used, but uranyl nitrate is a good choice. The trick with the paper is allegedly to find one which contains pig gelatin. I have been fixing out an EMaks paper and getting sharper images than with some of the others. But I'm still in the early stages of this myself, with not much time either, since I'm also involved in Ciba, Type C, and silver gelatin printing.