U of S | Mailing List Archive | alt-photo-process-l | Re: brush vs tray size for gum

Re: brush vs tray size for gum

 About whether sizing needs to be "aged" before printing:
Katharine, I should have been clearer: I was referring more specifically to the hardening action of particular hardeners needing "aging"--in other words, chrome alum if I remember correctly hardens over a period of time, not instantly. I have always felt glut hardened instantly, because in my experience the paper is usable right away. But Carmen's experience with glut and a magenta square (using Black Magic glut, though) made me question the possibility of glut needing "aging". If I remember correctly, Ryuji concurred that glut doesn't need aging time.

Mark, as far as bubbles and a roller--I used a dollop of Everclear in my size to get rid of bubbles.

The time my brush sizing went on unevenly was when I sized outside, with the night getting cooler, and the gelatin cooling down too rapidly on the paper.

Kerik, I have read of two people who don't print gum in the summer due to "muddy" prints--in other words, from what I can ascertain, the increased humidity/heat created more hardening of the gum layer than their normal practice had come to expect. Candace, the implication is that the images due to humidity/heat were lower contrast. It would be equivalent to non-image hardening or fog, in theory at least.

Sometimes I'll have a layer that decides for no apparent reason to "stick around" for a whole lot longer than I want it to. It will eventually release from the highlights with no staining but gum can be predictable for me, until it is not.

I remember in the old books talk of "spontaneous hardening" and they would blame it on unsuitable pigments, and one guy even wrote this whole theory on how the minute you put dichromate into the gum/pigment mix, it hardens, and then it get less hard...pretty funny and I only read this idea once so apparently his explanation didn't hold water.

Carmen,I have not sized over 16x20 because that is the biggest contact print frame I have--but I use a 3 inch foam brush, liberally soak it in the hot gelatin, and brush away. It does fine for that size. It is very wet though--I pour out about a cup of hot gelatin from my thermos, so it goes on quite hot. I feel for you, doing huge sizes...

Matt, glad to hear someone else aside from myself and a couple others has seen the glyoxal yellowing. When it happens it is pretty dramatic, huh.

BTW, does anyone on this list work with cadavers and aren't they soaked in formaldehyde and does one have to wear gas masks while working on them? I would think a whole body soak of the stuff would fume off a lot more than a bunch of sized paper...but one of these days I was going to try Kerik's method of drops of formaldehyde--such a quick and classy little method...