Re: Gum chemistry is simple and easy and Gloy

Correction:

On Mar 20, 2006, at 10:43 AM, Katharine Thayer wrote:

> I didn't know what David was referring back to, but since it was
> about gloy, I decided it must have been Terry, so I looked in the
> junk folder and here it was. (My mail program puts anything with an
> aol address into the junk automatically.)
>
> Now let me see.... ladders.... bits sticking out....atoms break
> off... more pigment makes the gum less soluble....

This is a typo of course; what he said was that more pigment makes
the gum less *in*soluble, not less soluble, and that's what I meant
to write, but the typo doesn't change the point I was making.

At any rate, if more pigment makes the gum less insoluble, then why
do most gum teachers, including myself, recommend reducing the
exposure when increasing the pigment to darken the shadows? If you
don't reduce the exposure, you run the risk of blocking not only the
shadows but the midtones as well. If more pigment makes the gum less
insoluble, it's hard to see why you'd need to reduce the exposure
when adding more pigment.
Katharine
Received on Mon Mar 20 13:33:24 2006