I know this thread is about developers for dry plate tintypes, but if you are currently using ready made gelatin emulsion, you can save mountains of money by making you own gelatin based silver bromide emulsion I describe in Christopher James' Book on Alternative Photographic Processes. We will also be teaching a workshop in gelatin emulsion making in 2013. Check out the George Eastman House workshop page from time to time to see new listings.

http://www.eastmanhouse.org/events/e...hoto-workshops