U of S | Mailing List Archive | alt-photo-process-l | Re: Pigment/gum ratios

Re: Pigment/gum ratios



P.S. Another example, with visual, of how I alter the stock mix for different uses. My stock mix of ivory black prints black, but when I want a rich brown color, I add a little gum to the stock mix. The warm black turns a rich brown when slightly diluted, that's still dark enough to print nicely as a one-coat. This is actually a reject print, but it shows the effect I'm talking about well enough, even though it's otherwise flawed:

http://www.pacifier.com/~kthayer/html/kids.html
Katharine

On Feb 14, 2007, at 10:46 AM, Katharine Thayer wrote:


Then I use that stock mix in various ways, depending on what I'm doing. For a one-coat gum, I'll use the stock mix straight. For a multiple gum, I'll most often use a diluted mix, because while in a one-coat gum you want the greatest DMax that a pigment is capable of, in multiple gums, and especially in tricolor, to use each pigment at the maximum color saturation would result in poor tonal balance (too dark) and probably poor color balance as well, because pthalo especially needs to be backed way down to balance against the other two colors. And I will adjust the mix to achieve different aesthetic goals; for example, for the very high-key work I was doing 2001-2004, I added a huge amount of gum to the mix (like 1:10) to achieve very pale, almost invisible, colors. And I often mix the mixes to create different colors, as well.
Katharine