</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (smieglitz @ Oct 18 2002, 08:36 PM)</td></tr><tr><td id='QUOTE'>
I've experimented with a few sizing agents, mainly for gum printing. I've always found the Knox the least suitable. I believe it is around 80 bloom (although I can't remember where I read that several years ago). I think the best thing is to just bite the bullet and go with the 250 from B&S as it is consistent. Another alternative which I use for gum printing is canvas hide glue sizing and it is my favorite when I want to try avoiding subsequent hardening. It is available in most art supply stores, is less expensive and apparently harder than the gelatins, but slightly yellower.
As far as the hardener, I'm not sure that glyoxal is really less toxic than formalin. It doesn't irritate as quickly as formaldehyde, but if you can smell it, you are probably lacking adequate ventilation for using either. (Just like some newer artists' paint solvents don't smell as bad as traditional turpentines so some people expose themselves to the fumes longer...there's some reciprocity going on there.) Glyoxal certainly doesn't harden as well in my experience.
Well I actually bit the bullet and ordered Cranes Platinite and Socorro Platinium. Since I am ordering from B&S might as well order all from one supplier and forget about the sizing, boy is that boring!
I am curious about your glue thing though, how did you come across this as sizing? how about permanence?
I dont know if you do gum over pt/pd, Kerik Kouklis and others are producing some wonderful work with this combination but some people are having trouble with the gum bleaching the pt as dichromate is a bleaching agent. I wonder if the glue would fasten the pt and prevent it from bleaching? hmmm......ah well, that will be another project to be done....
Thanks smieglitz for the food for thought.