Quote Originally Posted by titrisol
I have only tested the normal instant coffee.
The folger's crystals are reccommended but I bought Harris-teeter brand instant coffee and it worked as well.

According to the research carried out by Don Qualls, decaf should work to, since the main developer agent is caffeic acid and the tannins in coffee.
Will espresso increase contrast? And is steamed milk affecting the tonal curve?