Re: Gum -- Drying temperature

On Wed, 5 Nov 2003, Gary Nored wrote:
>
> Sooo, went back, and made another sheet at the same ratio, but
> with slightly more pigment. Again, not thinking clearly enough to
> realize that I was adding another variable here, I put the sheet in
> the closet to dry. This time, I turned the machine down (so the
> room was cooler) and I took the paper out faster.
>
> VIOLA! Best print I ever got. Amazingly sharp, not grainy at all,
> wider dynamic range than I've ever seen. A little staining, but the
> paper was somewhat sloppily sized, which I've discovered is a no-
> no.
>
> So now I wonder--how important are the DRYING conditions to gum
> bichromate printing? How important is temperature? Time-to-dry?
> Time between drying and exposure?

You've just answered those questions, the summary being "very." That
is, even if it prints well, a paper that's been exposed as soon as dry
will, odds are, print differently from one left 2 hours. Heat & humidity
above normal will cause staining, odds are, but -- where are you? Odds
are that unless you're in the Amazon, humidity isn't so high as to make it
worth dinking around with dehumidifier, which is an accident waiting to
happen... Rather put an ordinary small fan , just regular, no heat, in the
space. Print will dry in very few minutes & print with fewest surprises.

However, some variation amounting to extra exposure can be compensated for
by longer development. How long are you developing? (It occurs to me also
tht where you say you got no image, you might have gotten one by
developing longer... some ignorami say if it's not developed at 1/2 hour
it won't. That's nonsense. I'd say if it doesn't develop in 24 hours it
won't, tho there's rarely a time you can't get SOME image, however crude,
by soaking long, then brushing.)

J.
Received on Thu Nov 6 00:39:09 2003