RA-4 chemistry???

[Bobby Ironsights]

What'n the hell is RA-4 chemistry? I've seen the advertisement on freestyle....colour chemistry as low as 20 degrees C!

But I didn't find a wikipedia article, on it, and that's unusual.

 

[Alpha]

Everything you could possibly need to know about the chemistry aspects of RA-4 processing can be found here:
http://www.kodak.com/global/en/professional/support/techPubs/j39/j39.jhtml

Learning to filter properly during printing is a different story.