Question about Glyoxal
I have a couple of quick questions about using glyoxal for sizing.
First, for those who dip the paper in a bath of glyoxal, can you reserve the solution and reuse it or does it need to be thrown out after each sizing session?
Second, if you have to throw it out, is it ok to send it down the drain or do I need to collect it and take it to a hazardous waste facility?
My apologies if these questions have been addressed elsewhere. I have searched, but haven't turned up any answers. Up to now I've been using formalin as a hardener, but am wanting to give glyoxal a try.
Thank you in advance,
Heather can't answer about glyoxal because I haven't used it before. I was sizing with gelatin and hardening with formalin. I was adding formalin directly to the gelatin solution (0.2ml formalin per g of gelatin) then discard unused solution later - this is much quicker than sizing and hardening in separate steps and uses a lot less toxic substance. But then I started to size with PVA, it's very quick, non-toxic and effective. I use a locally available PVA glue for sizing, diluting it by 1+2 to 1+5 depending on the needed effect. There's a special PVA sizing available to printers in the States; it's Gamblin PVA size. It can be used full strength or diluted and I know several alt process printers who prefer this over the old gelatin sizing method. For which process you need to size the paper and which paper is that?
Hi Loris.. Thanks for the response.
Originally Posted by Loris Medici
I am sizing for gum bichromate, and I'm currently making my way through a stack of Fabriano Artistico extra white soft press. I am making a series of gum over cyanotypes.
I think I will try your suggestion to add the hardener directly to the gelatin solution since that will create less waste. I'd still kind of like to know the answers to my question above, in case this method does not go well for me and also just to increase my general knowledge about the matter. As of now, I am accustomed to brushing on my gelatin and then soaking the paper in a formalin bath (as described in the Non-Silver Manual).
I actually have a bottle of Gamblin PVA that I've been intending to try as well. I gave it a quick test several months ago, and wasn't impressed by the surface it gave my print, but I admit I was in the midst of several other printing projects and did not give it the time or attention it deserved. I used a 1:2 dilution, so maybe I should try diluting it more. If I end up using the PVA sizing.. should I use a coat before each layer of printing, or is one coat at the beginning sufficient?
Some people are using this paper (FAEW/SP) without any size. I think it somehow depends on your pigment choice too; my understanding is that carefully selected pigments leave no need of extra sizing with this already very hard sized paper. Never used it myself but I've heard many "yellowing" stories about glyoxal; again, my understanding was that the yellowing was caused by using too much or strong hardener and not washing / rinsing papers after hardening is over. Nevertheless, all this is to much effort for my liking, especially so in the context of gum printing - a quite straining process, already... BTW, the glue I use doesn't change the surface when diluted 1+3. (It's not Gamblin PVA size.)
Another two cents:
As previously mentioned, adding the hardener directly to the gelatin is much more efficient, eliminates a step in the process, and does away with having to fill a tray with malodorous aldehyde. IIRC, sodium or potassium metabisulfite (also call pyrosulfite) will neutralize aldehydes if disposal is an issue. Glyoxal can cause yellowing if used to excess, or with papers that contain a starch sizing. Rinsing afterwards will usually lessen the problem, though I would change hardeners if the yellowing becomes an issue.
My personal preference for hardening is glutaraldehyde - very potent and I've not encountered any yellowing issues.
Heather I've missed your last question: with my PVA glue, it's sufficient to size the paper at the very beginning, I don't re-size between layers; it makes the paper too slick and the first size keeps well for at least 6-7 layers - it's pretty waterproof.
Thanks so much for your responses, Ian and Loris.
I tried a couple of prints this morning... one without sizing and one sized with Gamblin PVA diluted 1:3. Both turned out decent, though the one with no sizing took much longer for the highlights to clear. The Gamblin seems promising at this point. After it dried, it didn't have the odd sheen that I remember it having the last time. I haven't put a second layer on yet though. One problem that I did have was how badly it made my paper buckle. This made it hard to spread my emulsion evenly.
My bottle of glyoxal should arrive sometime this week. I'm looking forward to experimenting and seeing which method I end up preferring.
Hi Heather, do you still develop the prints? If yes, for how much time in average? If the highlights clear in 20-30 minutes that's perfectly OK in my book...
Good luck, I'm sure you'll find a method that suits your needs,
P.S. The PVA glue that I use doesn't make the paper buckle, maybe you're using too much? It's quite hard to make 300gsm/140lb paper buckle...
It usually takes my prints about 45 minutes to develop. The print on unsized paper took well over 2 hours. The print sized with Gamblin took somewhere between 30-45 min. Anywhere up to an hour is fine with me. I'm using pretty cold water though, so I'm sure that lengthens the time.
I think I used somewhere around 1 or 1.5 teaspoons of the Gamblin mixture for a 8 in x 10 in print. Too much probably?
2 hours is long for sure. Seems that you'll need the sizing. If you want to speed development you can add a little (1 tablespoon?) bleach in the development bath, check often and when you see signs of clearing transfer the print to ordinary water. That speeds up things a lot, kind of a development seed.
Can't comment about your sizing amnt; I just dip the sponge brush to the size and brush on the paper, I do it by eye and feel.