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

Re: 3rd layer of gum

Thanks for your reply.
This happens whether the paper is sized or not. Yesterday I did a tricolor on Fabriano EW unsized in blue, red, yellow order (my usual order is yellow, red, blue) and the yellow (3rd) layer had just a little effect on the outcome and was developed in 15 min as opposed to the other layers at 30 min.
When I print Y, R, B the same thing happens on the last layer (B).
It always looks like the last layer needs another exposure of that particular color.
----- Original Message -----
From: "Katharine Thayer" <kthayer@pacifier.com>
Sent: Wednesday, October 07, 2009 9:30 AM
Subject: 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.
> k
> 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...
>> Thanks!
>> Paul