Re: Gum problem(s)

On Thu, 1 Dec 2005, Tom Sobota wrote:

> But I see that I did not express myself clearly as to the procedure. The idea
> is to spread a little of the gum/pigment/dichromate on a real newspaper,
> with a finger perhaps, let it dry and then verify if the written text on the
> newspaper still can be read or at least still can be seen through. Only then,
> after perhaps adjusting the pigment content in your mixture, you coat the
> definitive paper.

Now why didn't I think of that -- In fact I think I need to check the
original again (assuming I can lay hands on it), because the impression I
got was that they really did put the paper over it... though that may have
been only in my mind.

> Attempting to read a newspaper through a coated paper would have been
> impossible even for Demachy, I think. And futile, in a way, because the whole
> purpose of the test is to verify the transparency of the mixture before
> coating, not after.

Well actually, I always register a gum print on the light table, viewing
through the negative and the new coat of emulsion to the coat beneath (tho
it doesn't work very well over yellow, it does fine over red, and even
fine details can be read (tho I don't know about newspaper -- maybe the
print was larger in those days?). Anyway, I just assumed they put the
paper on the light table & stuck the newspaper under it. (Uh oh, their
"light tables" were vertical, using sunlight -- hmmmm.)
>
> P.S. Sorry but I cannot understand the meaning of 'but I suspect that the
> idea suffices'. 'suffices' as in 'sufficient'? You mean that 'the idea is
> enough'?

Exactly.... keeping the idea of the transparency in mind was probably
enough -- tho again, I myself don't print that way, and of course if
you're doing a tri-color gum with a halftone (or digital) negative, you
have a lot of solid opaque dots -- quite different I dare say.

>Please keep in mind that I'm one of those on this list that you was
> speaking of the other day: English is only my fourth language :-)

Sigh -- very intimidating, even humbling !

Judy
Received on Fri Dec 2 01:15:59 2005