U of S | Mailing List Archive | alt-photo-process-l | Re: 3rd layer of gum

Re: 3rd layer of gum

Paul, I've only seen this with nonabsorbent surfaces like glass and yupo, and only in areas where there are actually three layers of hardened gum. (for instance if there's an area that's all blue, where little or no yellow or red pigment have been deposited, there's no problem with adherence of the third (blue) layer, only in more neutral and mixed areas where there are equal amounts of all gum layers. I've never seen it with paper.

As Keith said, you can adjust for it either by exposing more or developing less. I also wonder about your sizing; it sounds like maybe your sizing isn't leaving enough tooth for all the layers of the gum to have some to hold onto.


On Oct 6, 2009, at 1:18 PM, Paul Viapiano wrote:

Hi all...

Why does the 3rd layer of a gum print always develop so quickly, or is subject to washing off so much more quickly than the other layers, whether with sized paper or not...? (regardless of printing order, as well...and these are all the same exposure time, too)

This has happened on several tricolors I've done now...