Re: What is a correct formula for gelatin+glutaraldehyde paper sizing

Job Westerduin

Oh i have a idea to neutralize the paper afterwards with a  bath of baking soda+water..

Or is that noy good idea?

Op vr 2 apr. 2021 19:47 schreef Job Westerduin via <>:

Hi thanks for answers,
I found a safety material sheet from Rollai-Maco from Germany. (Screenshot)

There is 2-5 pct of glut in there.
But the two another addidives might be give problems with sizing, this makes paper acid.

Op vr 2 apr. 2021 19:14 schreef Don Nelson <ac7zg@...>:
And you might want to mix smaller amounts as it starts to immediately crosslink in solution
I coat 2  12x15 sheets at a time with just 100ml size plus 0.8 gm glut, using a coating rod to spread. A hot rod with eliminate bubbles in the sizing
( rod is a RD90)

On Apr 2, 2021, at 10:10 AM, Don Nelson <ac7zg@...> wrote:

You can use up to 0.9 ml 3% glut solution per 100ml of gelatin sizing (I use 5% gelatin)
More than that and you will start forming polyglut. Polyglut will give a yellow stain in the size and cannot be removed.
Very little glut can actually be used. Two active bonding sites on the glut molecule means a lot of crosslinking activity with gelatin
Don Nelson 

On Apr 2, 2021, at 8:22 AM, job.westerduin@... wrote:

Hi, i have experimented with gum printing (trail and error,, and i will to start serious first gum printing with a cyanotype as starting layer base this weekend or later.

I have a pot glutaraldehyde from Rollei Black Magic emulsion set, that was left over from my previous silver photopaper enlarging hobby
How many glut and gelatin per 1 liter water.

Greeting Job from The Netherlands. 

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