Re: Sizing with unhardened gelatin

Jack Brubaker wrote:
>
> Katharine,
>
> How strong a gelatin coating did use for your unhardened sizing? I tried
> this once a few months ago and the gelatin softened enough when brushing on
> the gum that it mixed into the brushstrokes and didn't keep its integrity as
> a size. Did you brush on the gelatin?
>

Hmm,
I have a hard time imagining how this could happen. I don't doubt you,
understand, but it's so different from my experience I can't even
picture it.

When I was printing on unhardened gelatin size, early in my gum printing
experience, I did the sizing in tubs. Once the size was dry, it was
solid and kept its integrity not only through brushing on the gum
coating but through the soaking in cool water; it never even got slimy.
Which makes sense given that the melting point for gelatin is somewhere
above room temperature.

For this experiment, I brushed the gelatin on, thick enough that I could
see the color clearly (in other words, thicker than I would ordinarily
brush it for a usual size; ordinarily I would want the size to sink into
the paper rather than sitting on top of it). But again, there was no
softening of the gelatin either when brushing or when doing the gum
development, as was evident by the colored gelatin layer still being
intact in border and other unexposed areas after the gum prints were
finished.

I use one envelope of Knox (7 grams) per about 200 ml water.
Katharine
Received on Tue May 4 17:04:22 2004