U of S | Mailing List Archive | alt-photo-process-l | Re: brush vs tray size for gum

Re: brush vs tray size for gum

Carmen, a couple of comments:

I mix the glyoxal and gelatin together and apply in one step, and the glyoxal rinses fine; in other words for me the glyoxal doesn't have to be applied separately to get the benefit of rinsing. I don't bother with a separate rinse after sizing, though, because I've found that the yellowing disappears when the paper is printed and developed; in other words the yellow disappears in the normal water development for gum printing. Of course your paper may behave differently; if you've already tried mixing them and found it didn't rinse out, then never mind my comment of course.

I think the difficulty with brushing is definitely related to the size of your paper; the gelatin probably cools and gels before you can get it all brushed out. I have two large flat electric griddles that I put next to each other to keep paper warm while I'm brushing sizing on to keep it from setting up too fast, but you'd probably need four of these for your whole paper. Another, similar, idea: use a piece of plate glass bigger than your sheet of paper and put heating pads underneath to warm the glass.

On Sep 26, 2006, at 12:51 PM, Carmen Lizardo wrote:

Dear Chris and Kerik,
I would love to brush size my paper, specially because
use a full sheet of 22x30 inches when I print, and you
could only imaging how long that takes and how much
gelatin I need, but I can't seem to be able to get an
even coat, and mixing glyoxal and gelatin together is
out because I have to able to rise it off the gelatin
to prevent yellow stains.  Of course when I used Glut,
it was from black magic and that did not work. I also
felt it in ky eyes and throat and i not even the
sensitive type.  I am willing to try again, maybe with
a different glut?? Any pointers that you can give me
with the brushing??  I was thinking that it had to do
with the size of my paper. The gelatin gets hard
before I have time to cover the whole 22x30 sheet.
Thank you kindly,

--- "kerik@kerik.com" <kerik@kerik.com> wrote:


I agree that tray sizing is a lot of mess and hassle
for no substantial
benefit. Plus, why do the sizing in 2 steps when it
can be done in one? I
use either a glass rod (puddle pusher) and/or a
brush.  I add the hardener
(formaldehyde in my case) to the sizing just before
sizing each print.
Three drops of formaldehyde and 5 ml of 3% sizing
easily does an 8x10 to
11x14 print.  In these tiny amounts, exposure to
formaldehyde (or whatever
hardener one uses) is minimal. I get very even
sizing this way. A little
bit of curl to the paper, but nothing that causes
any problems.

I tried B.M. glut and did not like the results. It
resulted in slower
development and considerably more staining than with

As for sizing with unhardened gelatin, that sounds
like another in a long
line of T King's erroneous hyperboles.

Speaking of gum, I taught a gumover workshop in
Philladelphia this past
weekend for www.projectbasho.org. On sunday it was
80 degrees F and 82%
humidity in the darkroom. That's the first time I've
printed gum in
sauna-like conditions and it created some hassles
with very slow
development and the need to intervene with some
brute force measures
(brushes, fingernails, sandpaper). Anybody have
similar problems printing
gum in high humidity?  The conditions seemed to
cause problems with the
sizing in particular because development was much
closer to normal when I
did a single coat of gum on unsized paper right out
of the plastic bag. I'm
speculating that the humidity either prevented the
gelatin from hardening
completely or it allowed the gum solution to soak
into the sizing a bit
rather than sitting on top. Despite the problems, I
believe a good time was
had by all. Although I always want things to go
smoothly during the
workshops, it's good for the students to learn how
to deal with problems
when they come up.


Original Message:
From: Christina Z. Anderson zphoto@montana.net
Date: Tue, 26 Sep 2006 08:08:22 -0600
To: alt-photo-process-L@usask.ca
Subject: brush vs tray size for gum

Hi All,
This weekend was time for sizing paper, and since I
was doing small sizes
(11x14's) I decided to tray size instead of brush
size to see if it had any
added benefits to brush sizing.

I was sizing with gelatin glutaraldehyde as usual.
I did use a piece of it
right away, same day, and had no problem with the
sizing not being hardened
and producing "magenta squares" as did Carmen.
However, I was using glut
that I bought from a medical supply house (now
available at the
Photographer's Formulary) and not Black Magic.  The
gelatin on my paper was
not slimy in any way so I know it was hardened. I am
still not sure why
Carmen got that problem, and am wondering about the
suitability of Black
Magic, therefore, with its added sulfite. It sounds
like the same result I
had when I tried Terry King's advice to use
unhardened gelatin and got

With tray sizing and cautions with glut, I gelatin
sized the paper first,
and then the next day I soaked the sized paper
OUTSIDE in a tray of 50ml
glut to a gallon of water.  That worked well, but I
would only tray size if
the hardening part could be done outside to minimize
fumes produced by the
surface area of a whole tray of hardener, whatever
type--glut, gly,
formaldehyde. (When I brush size I keep the solution
capped inside a
and pour out a cup at once.) The gelatin paper went
in "slimy" feeling, and
went out unslimy.

The paper works fine but I learned a couple things:
paper tray sized with
gelatin will sink to the bottom, not float as does
brush sized paper
Arches) so if I am going to leave the paper soaking
for a while it needs to
be face up. I learned that the hard way. Back to
floaters and sinkers, Mark.

The paper does curl less than brush sized, but it
doesn't seem worth the
added trouble of trays. This is the only benefit I
can see.  Oh, maybe more
evenness of sizing?  I don't know this one
yet...will have to print all

My husband set up an ingenious "clothesline" for
me--a rung ladder on its
side has plenty of hanger-ready rungs.

I learned another thing the hard way:  I printed 4
prints on the unsized
shrunk paper with a cyanotype layer, put the paper
through the hot gelatin
sizing process and didn't THINK that the
140-whatever degree gelatin would
shrink the paper even more and make registration a
B---H but you bet it
did--warped and shrunk. Luckily only 4 prints
ruined. DUH. Or, as Clay

The bottom line is that brush sizing is sooo much
easier and works well and
uses way less gelatin--I sized 24 11x14s with a a
liter of 3%, and normally
I can do that many 16x20s with the same. I don't
think even with small
I would tray size...

That's all my truly exciting weekend experience!



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