I've switched over to gelatin/formalin for sizing my paper for gum printing - gel coat, dry, formalin soak, dry and repeat. I'm having much better results with this method than with gelatin/alum. Formalin is one of the few chemicals that really bothers me - one wiff and my eyes, nose and throat are on fire.
I got creative and tried using a plastic container in a method similar to drum-processing. So far, so good! I'm using a polyethylene wide mouthed container that protein-powder comes in. I curl the paper to the inside of the plastic container, add just a few ml of formalin sol'n, put the lid on, and swirl, rotate, roll etc., for a few minutes. NO Fumes and only a small amount of hardener solution is used.
Thought I'd pass this along in case anybody else wants to try this method.

Where do you get formalin? I'm just getting into gum printing and I am curious, in case I find I need to start sizing my own paper.

Where do you get formalin? I'm just getting into gum printing and I am curious, in case I find I need to start sizing my own paper.

Most chemical supplies firms carry formalin - around here it's Canadawide or Fisher Scientific. I was fortunate enough to get a small quantity of formalin from a veterinarian, rather than having to commit to purchasing a large quantity.

Just figured out that formalin is another name for formaldehyde. Thanks for the sizing tips; if I find I need to size the paper it'll be useful advice (not sure yet, but since so many people seem to do it for gum printing I figure it might be inevitable!).

I was able to find foramlin locally in a pet supply store. It's used to control fish parasites. Avoid the product called Formalin 3- this is only 3% formalin and much too dilute. The solution I got is around 37% and was ~$30 per 500ml.

I'm wondering if anybody has tried some of the higher aldehydes like propanal (and beyond) as hardeners for gelatin. Formalin is working okay for me, but I am finding that it's action continues over a period of days, sometimes resulting in a rather brittle gelatin.

I've switched over to gelatin/formalin for sizing my paper for gum printing - gel coat, dry, formalin soak, dry and repeat. I'm having much better results with this method than with gelatin/alum. Formalin is one of the few chemicals that really bothers me - one wiff and my eyes, nose and throat are on fire.
I got creative and tried using a plastic container in a method similar to drum-processing. So far, so good! I'm using a polyethylene wide mouthed container that protein-powder comes in. I curl the paper to the inside of the plastic container, add just a few ml of formalin sol'n, put the lid on, and swirl, rotate, roll etc., for a few minutes. NO Fumes and only a small amount of hardener solution is used.
Thought I'd pass this along in case anybody else wants to try this method.
Nice idea, but I don't really see an advantage in your technique.
I've tried hardening with formalin once in my bathroom, the vapors released during the drying process were reason enough for me to never do it again, inside. :)

Sidney

Nice idea, but I don't really see an advantage in your technique.
I've tried hardening with formalin once in my bathroom, the vapors released during the drying process were reason enough for me to never do it again, inside. :)

Sidney

When it's -20 degrees here, 'outside' work is not an option - inside with fume is the way to go - anything that reduces the amount of formalin is advantageous.:D

Two options:

1. Try adding formalin into the gelatin solution and use it one shot. I usually prepare 100ml 3% gelatin solution and add 0.5ml formalin into it, keep the solution warm on a coffe cup heater, coat the papers and hang. That way, you'll finish the job in one step. When done, I pour the gelatin, wash the vessel and put 1:5 diluted bleach in it - which dissolves the non-washed remainder hardened gelatin completely. I coat 10-20 15x11" sheets and hang indoors, you can feel formaldehyde outgassing (if in a small room) but it's way more manageable than using a separate hardening bath. Just don't stay in that room and definitely use a room that can be ventilated with a transom window (vasistas/fortochka)...

2. Use Gamblin PVA size (or any other PVAc based bookbinding glue diluted to your liking; just look at the specs and make sure it's pH neutral, transparent, flexible and waterproof...). It's quick, and very effective.

Regards,
Loris.

I've tried glutaraldehyde, which worked ok for gum, but I couldn't build up enough of a layer for carbon transfers and have it harden properly without yellowing. I also have used gyloxal quite a lot, but it's also has a tendency to yellow for some users.

Formalin works the best of everything I've tried, but I have a detached garage or probably couldn't use it. I got impatient over the weekend and brought some coated sheets into the darkroom to finish drying.. Even half-dry, the fumes gave me a headache that lasted for days.

In my case, the papers are completely free of formalin odour in about 24 hours. (Maybe earlier but I coat and hang in the evenings and don't return back to the papers before the next evening...)

Definitely consider PVAc size from Gamblin (or an improvised PVAc size by diluting an ordinary PVAc glue that fits into the criteria I stated before) for gum prints...

I've switched over to gelatin/formalin for sizing my paper for gum printing - gel coat, dry, formalin soak, dry and repeat. I'm having much better results with this method than with gelatin/alum. Formalin is one of the few chemicals that really bothers me - one wiff and my eyes, nose and throat are on fire.
I got creative and tried using a plastic container in a method similar to drum-processing. So far, so good! I'm using a polyethylene wide mouthed container that protein-powder comes in. I curl the paper to the inside of the plastic container, add just a few ml of formalin sol'n, put the lid on, and swirl, rotate, roll etc., for a few minutes. NO Fumes and only a small amount of hardener solution is used.
Thought I'd pass this along in case anybody else wants to try this method.

Glutaraldehyde is the best gelatin hardening agent I've used. Paper sized and hardened with glut is ready to use in about 8 hours. Typically though I wait until the following day to use the paper.

I've not used PVA to size with paper yet so I'm not going to parrot what has been the buzz lately about it.

Don Bryant

Here's a twist - I'm picking up some various sizings from a local papermaker/artist. As it turns out, she's also giving me 25 kg of alum! (Leftovers from an order that was never picked up). Given that, I might just be trying the alum method again... just after I installed a fume hood / drying unit this afternoon.

Ian if they have alkyl ketene dimer (AKD), it's a perfect sizing; non reactive and non toxic... Ask them!

Ian if they have alkyl ketene dimer (AKD), it's a perfect sizing; non reactive and non toxic... Ask them!

Loris, AKD is indeed what I'm going to get. It was explained to me that AKD is usually used in the wet-end of the paper-making process, but it may work as an after-treatment. I'm looking forward to trying it out, although I don't have a clue as to what dilution, time, etc.,etc.,

Having just watched a beautiful gum print slide down the drain - probably from excessive Gamblin PVA sizing, I'm willing to try anything :)

I don't use that particular product, but from what I've read, I think it's best to dilute it 1+2 or 1+3, in case you're a little bit heavy handed in coating the sizing; too much of it will behave right as you describe.

Got my little bottle of AKD. Instructions are "add 1.5 tablespoons to a litre of water, use 1/8 cup of this solution for each blender-full of pulp". Hmmm, interesting mix of units!
Any ideas out there how I should proceed - experience with treating with AKD?
I do have access to facilities to make paper, but, dang! I just want to get some decent prints done ;)

Glutaraldehyde is the best gelatin hardening agent I've used. Paper sized and hardened with glut is ready to use in about 8 hours. Typically though I wait until the following day to use the paper.

Don Bryant

I picked up some glut. WOW, that stuff is fast and furious. Seems pH plays no small role - I tilted basic with a pinch of carbonate - instant yellow gelatin (but it sure hardened up quick!), oh well, it's all research ;)

My process is to size with gelatin, chill, dry and then harden (rationale being that it makes more sense to cross-link while gelatin is tightly coiled) - so far I'm liking the end product more than when adding hardener to the liquid gelatin. It does seem to be very 'touchy' using glut though.

Any ideas, tips are most welcome :)


-Ian

I picked up some glut. WOW, that stuff is fast and furious. Seems pH plays no small role - I tilted basic with a pinch of carbonate - instant yellow gelatin (but it sure hardened up quick!), oh well, it's all research ;)

My process is to size with gelatin, chill, dry and then harden (rationale being that it makes more sense to cross-link while gelatin is tightly coiled) - so far I'm liking the end product more than when adding hardener to the liquid gelatin. It does seem to be very 'touchy' using glut though.

Any ideas, tips are most welcome :)


-Ian
I have settled on a 5% gelatin size with either 2% formalin or 1% glyoxal mixed with the sizing. I apply one light coat with a paint pad, let set for a couple of minutes, hang to dry (very fast), and wait 1-2 days before using. I have not seen any yellowing with the glyoxal. This barely alters the matte finish or the color of the watercolor paper. Increasing the thickness/concentration of the gelatin sizing will add an increasingly yellow tint to the paper that I don't like.

I picked up some glut. WOW, that stuff is fast and furious. Seems pH plays no small role - I tilted basic with a pinch of carbonate - instant yellow gelatin (but it sure hardened up quick!), oh well, it's all research ;)

My process is to size with gelatin, chill, dry and then harden (rationale being that it makes more sense to cross-link while gelatin is tightly coiled) - so far I'm liking the end product more than when adding hardener to the liquid gelatin. It does seem to be very 'touchy' using glut though.

Any ideas, tips are most welcome :)


-Ian

Ian, IMHO, you are going this the hard way. Add the glut to the hot gelatin and size in one step. If the gelatin is turning yellow instantly it sounds like you are using waaaaay to much glut.

PM me for more details about glut.

Don