U of S | Mailing List Archive | alt-photo-process-l | Re: Ruined 3rd tricolor gum print! Grrrr...

Re: Ruined 3rd tricolor gum print! Grrrr...

On Mon, 22 Sep 2008, Christina Z. Anderson wrote:

You are right to cut down phthalo. It is an incredibly concentrated pigment. However, I develop it longer if it is too strong and that seems to help.
They used to call it "covering power" (Ralph Mayer & co), and probably still do... As pure, orthodox pigment, phthalo blue has much more of it ("covering power") than yellow or any of the reds I think of, so, as Chris notes, you use less of it. On the 3rd hand, however, every company has its own notion of how much to include in the tube along with the stabilizers and emulsifiers and other gunk, altho it's cheap enough so they probably pile it on. Still, on the 5th hand, if you change brands (or IME even lot numbers of the same brand) you need to test again. (Tho you knew that).