Re: Substrate and gum

Judy Seigel (jseigel@panix.com)
Wed, 14 Aug 1996 19:52:28 -0400 (EDT)

On Thu, 15 Aug 1996, CHRISTOPHER TSOURAS wrote:
> In my humble experience what appears to be of paramount import is my=20
> initial shrinking of the paper. Regardless of the particular paper I=D5m=
> =20
> using (which more often is BFK Rives, Magnani Italia, or Strathmore=20
> Drawing) I place the paper in a deep tray of hot water (hot as possible)=20
> for a minimum of thirty minutes, turning the sheets every few minutes. =20
> The paper is then hung to dry. After which I bake the hell out it in an=20
> old platen print dryer for a minute or two. I suppose you could do the=20
> same in any dry mount press. I=D5m placing the paper between blotter paper=
> =20
> so the platen will not affect the papers surface. =20
>

Do you keep heating the water? In my experience after the first 10
minutes temperature has dropped considerably. In fact adding a whole
lot of paper in itself drops the temperature. How many sheets do you
shrink at a time?

I'm curious about the baking after the initial hot water shrink, about why
baking the dry paper shrinks it still more... Have you tried just the
baking alone? Have you measured further shrinkage after the baking? When
I measured, I found that the paper might either shrink or expand again
after rewetting and drying, presumably according to room temperature &
humidity.

> The next step, of course, is sizing & hard sizing the paper. After which=

When you say "hard sizing", you mean a bath in a hardener?

> After the final sizing I then=20
> punch my registration holes. The paper at this point is remarkably rigid=
> and I feel I really get clean punched and durable registration holes. =20

It occurs to me that the difference between our experience with the paper
may be due, at least in part, to the fact that you use several coats of
size (2?, 3?) which may itself be what makes the paper very rigid.... it's
embedded with hardened gelatine. (I use only one coat of gelatine,
because I prefer that surface for working on.)

> 100% cotton, like my king size cotton bed sheets=20
> which if washed in extremely hot water and dried with heat will end up=20
> queen size (shrunk in all directions). The heavy pre-shrinking=20

But you said you hung the paper to dry *before* heating.... ????

> allows me to consistently print=20
> large images with meticulously accurate registration using simple 2 pin=20
> registration.

How large is "large"?

Hope you don't mind all the questions, but this is all very new and
amazing.... Thanking you kindly in advance.....

Judy