PYRO TRIETHANOLAMINE FILM DEVELOPER is a formula published in Peterson's Photographic, July 1984 issue. Written by Paul Farber, the demand was so great for this developer, we made the kit with permission. Mr. Farber stated in his article that this developer was intended for the production of large negatives, but has also proved exceptionally good on small format. It has smooth grain structure and full emulsion-speed capability. It lasts longer than other pyro developers and can be replenished just by adding fresh developer to make up the lost volume, and this can go on for years.