AZO Contact Paper - why use it?
AZO has been made by Kodak for 100 years or so. It is too slow for enlarger use, comes in only single weight glossy, and its availability is very limited. So what's the reason many photographers have re-discovered it?
The simple fact is that it produces breathtaking results. When I first started using it, as a result of reading Michael Smith's great article [listed below], I realized it was what I had been looking for ever since I started large format: extreme detail with almost three-dimensional feel. In fact, some of my prints give the feeling you could just walk right into them.
AZO has several unique properties. One is that it doesn't go bad. I have printed on AZO from the 1920s! In fact, many AZO printers prefer paper that is somewhat aged. Another property is that the contrast grades don't quite correspond to the ones we are used to on enlarging paper. I seldom use contrast 4 [and it is hard to get anymore], and contrast 1 isn't the dull item that it is with multicontrast paper, but instead softens harshness beautifully, especially with negatives produced with modern lenses.
Azo works great with other developers, but I find it works particularly well with an Amidol based one, and [although I mix my own] they are available from the Photographer's Formulary [contact is listed under our LINKS section]. The formula Michael Smith recommends [the one that I use] is listed in his article:
http://www.michaelandpaula.com/index_skip.html
[refer to the article on printing with 100 year old paper]