Re: Gum preparation

Katharine,

like you I know I have a good eye for some things. I could in my prime align
a peg to within 1/8 of an inch between two other pegs separated by a 100
feets. Good, maybe but what you do is out of this world, how much would you
say one can be off on a 8" x 10" print before people start noticing
misalignment. Base on other ideas, it is said we can resolve 5 lines per
milimeter, Sandy King wrote the other day it could go as high as 20 lines
per mm, that less then 1/1000 of an inch.

Find me an industry anywhere in the world that as to build parts or objects
within tolerance of 1/1000 or even only 1/250 (5 l/mm) of an inch and there
quality control is done by eyeball...

In your favor I'll add this, some time back you said the relative humidity
is pretty high and constant where you live, if it's near a 100% you probably
don't have shrinking problem to begin with. This would explain away your
apparent supernatural habilities.

Regards
Yves

----- Original Message -----
From: "Katharine Thayer" <kthayer@pacifier.com>
To: <alt-photo-process-l@usask.ca>
Sent: Friday, April 28, 2006 6:52 PM
Subject: Re: Gum preparation

> I've probably said here before that I've never preshrunk paper and
> that when I was in full production with tricolors, I could tell just
> by the feel of the paper when it would be the right size to recoat.
> kt
>
>
> On Apr 28, 2006, at 3:43 PM, Judy Seigel wrote:
>
> >
> > On Fri, 28 Apr 2006, Yves Gauvreau wrote:
> >
> >
> >> I notice the paper I used up to now was changing in size quite a
> >> bit. I
> >> simply couldn't do more then a single exposure of a 4x5 step
> >> tablet on it,
> >> this mean a larger negative would be a lot worst.
> >>
> >
> > Yves, any paper in any dimension no matter how well soaked or
> > boiled or treated with incantations, will almost certainly change
> > size if it's not at the same level of dryness (or humidity) when
> > you coat. If the humidity is constant where you live, timing the
> > interval between coats may suffice. Or set up some standard
> > procedure, which should also help....
> >
> > Some years ago I tested 4 different papers with & without presoak
> > and measured at various stages-- after coating, after drying, after
> > developing, etc. The paper could expand or contract throughout the
> > process. We only get a "set" dimension by luck, or paying attention
> > -- or holding the paper rigid, which is another production.
> >
> > J.
> >
Received on Sat Apr 29 07:34:33 2006