Re: Clearing dichromate

Judy Seigel (jseigel@panix.com)
Fri, 7 Jun 1996 01:38:12 -0400 (EDT)

On Fri, 7 Jun 1996, TERRY KING wrote:

> Pete
>
> I forgot to mention that as one can reasonably expect good gradation over a
> range of little more than 0.7 from the negative in a a gum print, if one exposes
> a step wedge onto dichromated gum without pigment to obtain an impression of
> every step across the range, then you are over exposing for nearly two thirds
> of the steps.
>
> Terry

Terry, I agree with you that there seems to be no dichromate stain
remaining in a well-developed gum print -- in fact in our water it
doesn't take all those trickling hours. If the thing isn't overexposed,
and isn't over-dichromated, an hour or so in water generally clears down
to naked pigment.

However, my arithmetic says the negative range of .7 you refer to above
would be less than 5 steps on the 21-step. Depending on the pigment,
paper, mix, etc. you can get a bunch more than that. Especially if you
don't mind some shouldering. (But, ahem, maybe not with Gloy.)

Judy