Hi y'all
or
Good morning Everybody
I will present this as a dialogue to give dramatic strength !
Subject: Re: Gum prep and Gloy substitute & tempera
Judy : Terry, I've been preoccupied with mundane events & let you get away with
murder here...
On Sat, 24 Feb 1996, TERRY KING wrote:
> 300 gsm papers often do not need stretching.
Do you mean "stretching" or "shrinking"? I haven't yet found a 300gsm
paper (& yes, I have tried some) that won't shrink.
Terry: Same difference, the paper tries to shrink but you don't let it so it
stretches. I have, on the papers that have gone on about, found that if you
use heavy estar base, 11 thou or 18 micron, film and a vacuum press or a contact
frame or heavy float glass, the paper,and that means your print, is stable at
140 lb / 300 gsm. I have the experience of more than twenty years. The proof of
the pudding is in the eating. Suck it and see. If you insist on using floppy
film you can expect difficulties. Viva Kodak ! ! ! or Typon ! ! !
Pre-coating in the way I suggested recently maintains the stability so that you
can use floppy film without stretching.
Judy : And could we please remember that when Larry says "three days," he is
not
laboring for the duration of three days. He is doing an operation that can
take from 10 minutes to 1 hour (depending on amount of paper sized) over a
period of 3 days, or for that matter a month ......or more.
If this includes two coats of gelatine, let me note, BTW, that in my
experience two coats of gelatine is too much -- makes the paper too
contrasty. If you need more gelatine, do another coat in progress.
Terry : I inferred from what LARRY said that he did not want to wait three days
before he could get down to real work rather than preparation. The guy Peter F
was on about took over a week. I do not think any of us inferred that he was
slaving over a hot bockingford for a week without interruption. I never use two
coats of gelatine. Three for oil prints perhaps; so I don't know where that bit
came from.
Judy: > Gloy
>
> For a first hardening coat you could try PVA which I was told is an acronym
for
> poly vinyl acetate or alcohol which is the basis of Gloy. Mix the PVA powder
as
> if it were powdered gum arabic, ie 50/50 with water. try that for size (sorry)
> as it is seven years since I did it. Then mix the resulting gum 50/50 with a
> strong solution of ammonium dichromate. Coat the paper and dry in the dark.
> Expose until the colour changes slightly, then wash until the dichromate stain
Terry, I doubt that the gloy *shrinks* paper any more than
gelatine/glyoxal does, probably less in fact. So would you explain again
why gloy is easier/better?
Terry : I did not suggest that it did anything other than keep the paper stable.
The thought occurs that here we have a pretty stable 60 % humidity. That could
give me a built in advantage.
There is a flock of jays having a fight outside the window. Noisy buggers!
Judy: In fact, since Henkel admits adding colorants, I'd ask do we necessarily
want that added tone? (Gelatine is colorless, colourless too.) And while
I'm on the subject, let me point out that residual dichromate stain from
the gloy hardening affects your image throughout the printing process,
even though it can be entirely cleared at the end. Not being as
clairvoyant as I might wish, I like to judge color as I go along, by
effect.......
Terry: I did my tests by making a difficult print with critical highlights,
strong shadow and details in the shadows and the highlights.
Given variations I needed in colour contrast, the print needed eight exposures.
The Gloy worked better from all standpoints.
The added tone at the thickness we are using is imperceptible, even by itself,
when compared with gelatine.
The dichromate tone washes out sufficiently to be able to make colour judgements
in less than two hours. Do they put funny thigs in NY water ?
Judy: > paper treated in this way should not need stretching. The whole
preparation
> process should not take more than two or three hours.
>
or about what gelatine plus hardener would take.....
Terry: So ? I have not put my oar in on that one. Not my fault Miss !
Judy: > I rarely stretch paper but if the paper is stuck down at the edges
with brown
> paper gummed strip available from 'artists colour men' and etching suppliers
OK, I know you meant to say "artists' color persons."
Terry: No, that's why I put it quotes. It's a quaint term they still use !
One paper wholesaler had a reference to a rougher version of its platinotype
paper in its catalogue. Turned out they had not amended that page since 1910.
Judy: > and then lightly wetted with a brush on one surface only, the paper
should
> stretch and dry overnight or in a couple of hours depending on the ambient
> humidity.
I'm not clear about the "paper gummed strip." Doesn't that wash off when
you put the paper in water to develop? And then your paper is free form
again?
Terry: Yes it does, but the whole point of stretching the paper in this way is
that it becomes stable as a result.
You do not have to do it again.
Now some parakeets are sqabbling in the garden. They have seen the cat and flown
away.
Us gummists are a funny lot.
Terry