RE: Gelatin size: brushed or immersed?

Carmen,

It's not necessary to size by immersion, in my experience. Here's how I do
it (copied from a previous post):

I size and harden using Livick's approach (at least I think that's where it
came from). I make up about 150 ml gelatin size, depending on how many
sheets I'm going to size. I usually use a 3% strength of 250 bloom gelatin.
I heat it to ~130 to 140 degrees F (55 - 60 degrees C) on a small coffee mug
warmer. This device keeps the sizing from getting too hot (which may or may
not be a problem, but I'd rather not boil it). In order to reduce bubbles in
the solution and the resulting gelatin "sparklies" on the print, I add
Everclear to the sizing solution at a ratio of about 1:20.

For a 14"x17" print I measure out about 10 ml of sizing, then I add the
hardener to that. I prefer formaldehyde over glyoxal because I've had the
yellowing issue with glyoxal, and enough has already been said about that.
And I've not seen any hard evidence that glyoxal is a safer compound than
formaldehyde. Lack of evidence is not proof. Formaldehyde is used much more
widely, so it's health effects have been studied in much more detail than
glyoxal. And the fact that glyoxal doesn't smell means that you don't really
know when you're being exposed to its vapors, which may or may not be
harmful. Both compounds work equally well as hardeners in my experience.

I add the hardener at the rate of 1 ml per 1.5 gm of gelatin. This reduces
to approximately 6 drops per every 10 ml of 3% size. I then coat the paper
with sizing using a glass rod (aka puddle pusher) followed by a little hake
brushing, if necessary. Using the formaldehyde in such small quantities
results in very little odor in the room and very little chemical exposure
for me. As a precaution, I use an air-purifying respirator with cartridges
designed for formaldehyde when I'm sizing my paper. But, the next day after
sizing and letting the paper dry in my darkroom, I detect no formaldehyde
odors.

I work mostly with Fab. Extra White and get no staining or speckling
problems. I also use Rives BFK and Whatman's watercolor. While BFK can be
susceptible to some staining/speckling, this is a rare occurrence for me.

I've not tried chrome alum or glut. I'm from the "if it ain't broke, don't
fix it" school, so haven't found the need to fiddle with those compounds.
For me, this is a very simple, reliable approach to a smooth and even sizing
with very little chemical exposure. If you pump your own gas or drink
chlorinated water, I suspect that your exposure to potential carcinogens is
many times greater than sizing paper in this way.

All that being said, USE THESE CHEMICALS AT YOUR OWN RISK AND USE THE PROPER
PERSONAL PROTECTIVE EQUIPMENT. One of Clay's mean lawyers told me to say
that. :-)

Kerik Kouklis
www.kerik.com
 

> -----Original Message-----
> From: Carmen Lizardo [mailto:carmenlizardo@yahoo.com]
> Sent: Friday, September 23, 2005 10:55 AM
> To: alt-photo-process-l@skyway.usask.ca
> Subject: Gelatin size: brushed or immersed?
>
> Dear List,
> First, thank you all for all of the help with my "cyano first
> coat dilemma". Its solved now. I am using Fabriano
> Artistitco, 140 lb (much chaper than the 300lb, although I
> got the heavier paper to print really well with a white
> vinegar pre -coat) now I have gelatin questions:
>
> I started to size my paper today, by immersing it into the
> gelatin solution, but since my sheets are so big, 22x30",
> this procedure requires a lot of gelatin to fill my tray.
> Also, it is kind of hard to do such big sheets by myself. I
> know that some of you brush the gelatin solution on the
> paper, which right now seems easer to do. What are the
> adventages and disadvantages of each method? And, can you
> offer any advise in how to do eather merhod more efficiently?
> I am planning to harden the gelatin with glyoxal (by
> immersion)
> Thank you again for all of your help.
> Carmen
Received on Fri Sep 23 12:13:06 2005