Re: Gesso sizing (Katharine)

On Jan 19, 2006, at 11:31 AM, John Brewer wrote:

> Hi Katharine
>
> I've just noticed your comments about using a mixture of gelatine
> and gesso as a size. What ratio of gelatine to gesso do you use?

I use about 30-40 ml gesso in 150-200 ml 3.5% gelatin.

> Does this mixture need hardening?

This is an open question. Those of us who use this combination don't
harden it, and certainly there hasn't been anything in my gum
printing practice that dictates the hardening of the combination;
that is, the sizing works quite well without further hardening. But
I've also sized with unhardened gelatin without finding any practice-
driven need to harden it, and have relied on the hardening it
receives in the gum printing process (somewhere I have demonstration
visuals to show that the gelatin is hardened by the dichromate in the
gum process) for hardening for purposes of retarding mold and such. I
don't know if this would be the case for the gelatin that's mixed
with the gesso, but I don't know why not either.
Katharine
Received on Thu Jan 19 13:54:50 2006