Re: Gum variables

Wayde Allen (allen@boulder.nist.gov)
Wed, 10 Jun 1998 13:39:46 -0600 (MDT)

On Wed, 10 Jun 1998 FotoDave@aol.com wrote:

> In a message dated 98-06-10 13:18:01 EDT, stwang@CLEMSON.EDU writes:
>
> << What kind of light are you using for gum? My gum/ammonium dichromate
> exposures run between 1-1/2 to 3 minutes in the NUARC, and that's fast
> enough!
> >>
>
> I just use banks of BL light, and it takes me 4-10 minutes with pot.
> dichromate.

I've been using a 275 W GE sunlamp about 24 inches above the print frame.
Exposures have been about 15 minutes. Sensitizer is 13% (saturated ?)
potassium dichromate solution.

Judy's Post Factory newsletter was what prompted me to try gum so I'm
still looking for the "typical" exposure to use.

- Wayde
(wallen@boulder.nist.gov)