Re: Newbie Gum fun Continued
Trevor, I brush size, with 4 pckts Knox gelatin to 1 liter water (or 1 pckt per cup). I add to this anywhere from 6ml-28ml 2.5% glutaraldehyde, keeping all in a thermos hot and contained. I use this in good ventilation. I also add some alcohol to keep down on the bubbles--50ml Everclear or rubbing alcohol per liter. I use a foam brush. I do preshrink the paper always, but some find Fabriano Artistico not to require it. I did that once and had to throw all my prints away. With larger gums it is a must, and some preshrink twice. If you are off 1/8 inch it is a pain in the popo and not any trouble to preshrink paper in my opinion. I tray sized once (hard for me to do because I do large gums so it requires a LOT of gelatin and a way to keep that large size warm , too) and I did like the fact that the paper lay flatter, but interestingly, I found that it did not protect as well as brush sized paper. My guess is that my brush sizing is hardening as it cools and lays on top of the paper better than gets absorbed. I occasionally do a print on unsized paper and have yet to feel that it looks better than a sized paper print in a side by side, but you can fudge it pretty well. However, this is because I do use a pretty heavily pigmented load in my gum layers. You can get by without sizing, perhaps, with a lightly pigmented layer, especially if you do a first coat VERY light pigment and long exposure to sort of cover the paper with a layer of hardened gum/image, but it'd have to have gum hardened in highlights, too, where staining will occur. But the best is to shrink and size and forget about it. One thing I find beginning gummists mix up is "staining" with "overexposure". They look different, and soon you can tell what you have, but if upon development you hardly get an image to show up, suspect overexposure. I have a class finishing up right now and they have got amazing gum prints their first forays into it with this procedure so I know it works for others than myself. I also had a funny--a former student donated her alt supplies to the department and in there was a stack of sized paper hardened with glyoxal (former professor's method) and it was butterscotch yellow, I kid you not, so if you use glyoxal as a size hardener, be sure to use the paper right away to prevent this. Or do Judy's method of sizing and hardening and then rinsing it. The former professor did teach a separate hardener bath, even, but this still produced crummy paper. Go to this URL and scroll down and see what yellowing looks like. http://czaphotography.com/show.php?what=learning&which=1 About the 10th image down is a comparison of yellowing. I know, this page is not a "pretty sight" but Jacek can also see spotty Arches paper on here, too, that I photographed through my kitchen screen door to show the translucent spots, and the perils of using too hot water to shrink, etc. etc. including a downloadable free gum process paper. I can't wait til the semester ends--only 3 more weeks and I will be free to gum print ad nauseum again... Chris CZAphotography.com ----- Original Message ----- From: "trevor cunningham" <tr_cunningham@yahoo.com> To: <alt-photo-process-l@usask.ca> Sent: Tuesday, April 24, 2007 2:39 AM Subject: Re: Newbie Gum fun Continued Been following this. I've done a gum or two and am not encouraged by the results. I'm interested in the whole sizing element. I know many papers come already sized, but either the sizing is inadequate for gums or it is lost in the shrinking process. When sizing, it's dipped into the gelatin, then a seperate hardener bath? or hardener is mixed with the gelatin solution?
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