Re: Substrate and gum

Terry King (101522.2625@CompuServe.COM)
14 Aug 96 03:57:46 EDT

Judy said :

>I airdry the stretched paper, that is, just leave it until it dries
>without any application of heat, and yet I find that it buckles nevertheless
> -- as I described several days ago. Which is to say, I don't think it's
>heat, steam or heated steam causes the buckling when paper is taped around
>the edges.

I use 140 lb ( 300 gsm ) paper as early on I found that it does not buckle in
the stream of warm air from the fan heater, which I use to ensure that the gum
after short exposures is hard enough not to run and can stand handling, but then
I do not use a substrate and the paper is not taped or stuck down. I found that
the paper does buckle if you wet in on both sides when tring to stretch it but
not if you wet in one side only. I am not sure in what way that is relevant but
it may prove helpful.

>As for getting a bubble in drymounted paper, it should help to cool it
>under a weight, like a sheet of plate glass.

With heavy based film the pressure from the quarter inch, 5 mm plate glass which
I use under my lamps, will make the paper accommodate itself to the film.

Terry King

Judy