Re: Gum contrast - not that it hasn't been beaten to death

Good morning all!

Happy New Year, too.

Just back from vacation, so have not read all posts, but this caught my eye.
Reason being, Paul Anderson said in 1935 that if you print on a totally
smooth surface, you won't get a tonal gum print because the depth is not
there between paper bumps to hold varying depths of hardened pigment.
Henney says same in 1939, that a print on perfectly smooth paper will
produce a silhouette because there is no depth of bumps in the paper to hold
varying thicknesses of emulsion. I know this was repeated a couple other
times in my research, too. Suffice it to say, I thought one day I would try
printing gum on glass and see if this were the case (one of the authors
talked about glass), or yet another gum myth. I found it intriguing when I
read it time and again, anyway.

I took out some prints that I had done recently on different papers, and the
contrast is higher on the smoother, less absorbent papers. For instance,
testing a gampi paper against hot pressed water color paper, the hot pressed
has greater contrast. When using sized papers vs unsized (I had some old
sized stuff I was testing, don't size now) the sized always gave greater
contrast. A 100% gampi paper, very thin onion skin stuff, produced lower
contrast, albeit smooth, because when you brush on the gum/pigment mix, it
totally absorbs thru the paper. When I have brushed stuff on Clearprint, it
sits on the surface at the offset, very annoying. Actually, the gampi is
annoying too, for the opposite reason...so perhaps some of the differences
in contrast are due to absorbency as well as smoothness, glass being totally
non absorbent.

Since I'll be concentrating on gum this semester, maybe I'll just have to
test these things...but as we all seem to find out, our results are our
results (YMMV). But if my results vary, it doesn't mean that my results are
the correct ones, nor someone else's are incorrect, just that there is more
than one result possible. At least, that is the stance I am taking. This
list has shown me truth in gum is postmodern--relative, not absolute.
Chris
PS Sandy, go tigers! Yeah! I watched that 4 hr game!

----- Original Message -----
From: "Sam Wang" <stwang1@bellsouth.net>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Sunday, January 04, 2004 3:16 PM
Subject: Gum contrast - not that it hasn't been beaten to death

> While I was test printing gum on the Clearprint Vellum, it finally dawned
on me, that the more
> smooth the paper, the higher contrast it gives in gum. Maybe that's why
those who sized their
> papers needed to lower the contrast of the emulsion by loading it with
dichromate.
>
> Gum on the drafting vellum works, but a normal negative (for me it means
a density range of
> about 1.0) gave extremely high contrast results, almost like lith films
developed in AB developer -
> no mid-tones.
>
> So, that's another variable for the gum prpcess. With digital negatives
that's of no concern though,
> just another factor in the mix.
>
> Sam Wang
>
>
Received on Tue Jan 6 09:54:29 2004