Judy Seigel (jseigel@panix.com)
Tue, 19 Jan 1999 22:17:05 -0500 (EST)
On Tue, 19 Jan 1999, Hamish Stewart wrote:
> SNIP
> >
> >I learned this by the way from a student, who got it who knows where --
> >her mother I like to think. Anyway, in my experience, the business about
> >thicker gum is better is an error. I nearly always add water if I'm using
> >only half the emulsion as sensitizer. A higher ratio of gum is hard to
> >coat nicely, dries tacky before you want it to -- at least when printing
> >larger than 8x10, which takes longer to coat. The water helps.
>
> I find this interesting Judy. I have never diluted my gum with water -
> though I often use more sensitizer than gum/pigment. But your comments
> are useful as I have had problems with too thick a coat causing flaking -
> with your favourite paper - Bockingford (which I have decided to stop
> using forever - :-) ) I will have to give this a go. Sorry for missing it
> earlier, but what kind of ratio of water to the gum/pigment are we
> talking about here?
I think I said that yesterday, and I'd hate to contradict myself -- truth
to tell I mush the gum-pigment around and see how thick it is, which is
usually related to how much pigment worm is in it. As a rule I guess I add
about 2 drops of water for every 4 or 5 drops of gum. This with a mix of 1
part gum to 1 part sensitizer. On those rare occasions when I use 1 part
gum to *2* parts sensitizer, I wouldn't add water at all -- the sensitizer
does the diluting.
The point, aside from making it easier to coat, is that a lot of times you
don't want your exposed & developing emulsion to be so thick -- if you're
planning to do any work in it, that is. It peels off too easily --
flaking, as you note. Also, just the least touch of a brush and it's like
going into a bowl of marshmallow fluff. Plus, the gum layers, if you're
doing several coats, can also build up too thickly. But this isn't
something I've done any kind of study on, simply a practice I've found
practical. Others may feel differently.
I recall someone saying recently he mixes his gum 18 degrees baume.
Judy
This archive was generated by hypermail 2.0b3 on Sat Nov 06 1999 - 10:06:43