Re: Hardening with glyoxal

> Chris, I've got several stacks of paper hardened with glyoxal sitting in
> messy piles all over the studio because what with 1 thing & another I have
> not cleaned it up... They are probably as white as they were the day I
> bought them, or if they have yellowed AT ALL I'd have to put them next to
> a new sheet to notice. They were sized and hardened at least a year ago,
> maybe more...BUT BUT BUT they were rinsed after the hardening.

Do you use aquarelle?
>
> Even before I figured out about rinsing after hardening, the paper didn't
> get bright yellow, so I'm not sure why yours did. One clue is that
> (following Tom Ferguson's lead) I only use 15 ml glyoxal per liter. So if
> you use stronger glyoxal maybe you get more yellow.

This is a possible.
>
> As for alkali causing the paper to turn orange -- you see that right away
> if it's mixed into the glyoxal solution, in fact the solution itself turns
> orange. I guess it's possible it could show up later, but that wasn't my
> experience. However another factor in yours getting a stronger color
> could be the amount of gelatin -- as I noticed that when I did get
> yellowing it was strongest where a bead of gelatin had formed along the
> edge... Do you double coat the gelatin? I coat only once. And which
> gelatin are you using? That could be a factor too. Mine is 3% Knox.

3% Knox. But I do brush coat twice.
>
> In any event, a long soak in water should clear the paper back to white --
> try a few hours.

I just put it in; we'll see if it budges.
>
> Oh, I see now you've mixed your glyoxal in with the gelatin... You can't
> rinse that off then, can you... another reason for not mixing... Why folks
> do that I don't know. It also means you can't save leftover gelatin for a
> few days in the refrigerator (which can be very convenient) -- or longer
> in the freezer.

It saves a step--you don't have to tray soak in a solution of glyoxal.

> Oh, and no distilled in any of it.... just sweet New York and Brooklyn tap
> water.
> Judy

OK, that eliminates one variable. But aren't you just a little leery of it
doing this years later?
Chris
Received on Mon Aug 16 06:15:54 2004