Re: Gum print formaline

Hi,
Yes, I have been using 6 ml of the 2.5% to a 2.8% gelatin (Knox brand). Let
me tell you my process--it may help:

I soak the gelatin and then heat it up to between 140 and 160; then I pour
it into a dedicated thermos. I squirt in the 6 ml glut and stir. Then I go
OUTSIDE and brush coat my paper. I pour in about 1/4 cup of the solution
into the top of the thermos and use that. The rest remains hot, until I
need to fill up the cup again.

This way I am exposed to very little glut. I hang the paper to dry on a
clothesline with baby hangers with 2 clothespins each.

I have been using either 2 coats or 1 coat of this, and it seems not to make
a difference. 2 coats may be overkill. On Artistico (the new) you
definitely only need one coat. 500ml of this coats 30 16x20 sheets one
time.

Of course, the reality of my sizing process is this: this week I struggled,
b----ing and moaning, with Fabriano Uno and sizing. I ran out of Artistico
and Jerry's Artarama did, too. In the meantime, it decided to get cold
here, so I was outside in the evening, trying to quickly size 30 16x20's. It
was getting darker and colder. The gelatin was deciding to make Jello when
it hit the paper. The humidity has been low so every time I print I have to
wet the back of the paper to get it to expand enough to fit the negative.
Not a good week.

One thing I did find out, interestingly, is that my gum layers are glossier
on Uno. Maybe the Jello sizing has contributed to that effect. But I want
my Fabriano Artistico back...
Chris

>> I have spent a full hour searching the archives and the FAQ about how to
>> use glutaraldehyde in gelatin sizing, but find no hints to how to do it .
>> Can someone who has not done enough community service in this area ,
>> please, help a newbe!
>
> Prepare a dilute glut (I use 2.5%) and slowly stir in this solution to
> the gelatin size before applying to the paper or any other
> substrate. Apply the size to the paper and let the size dry. Dried
> paper should be ready for use.
>
> The amount of glut is something you want to determine for your
> gelatin. Gelatins vary considerably in terms of its chemical
> properties. It is best to determine your best dose by testing with
> your gelatin size solution at the actual temperature of applying the
> size. (Photographic gelatins of large molecular size tend to respond
> to small amount of hardener, but food gelatin of low molecular size
> tends to take more hardener to take effect. Also, more dilute gelatin
> solution takes more hardener to harden.) I think at least one person
> on this list has experience with 2.5% glut and 2.8% food gelatin, so
> she may be able to help on the dose guideline.
> Don't forget about good ventilation -- if you can smell glut, you need
> ventilation.
> Ryuji Suzuki
Received on Thu Jan 27 08:13:58 2005