Re: Demachy and Maskell's postscript

Grafist@aol.com wrote:
>
> In a message dated 11/04/05 21:13:21 GMT Daylight Time, kthayer@pacifier.com
> writes:
>
> > Grafist@aol.com wrote:
> >
> > > Katherine,
> > > Try sizing with a 10% gelatine + 5% corn starch mix and see what
> you
> > get!
> >
> > >
> > > In a message dated 11/04/05 18:11:47 GMT Daylight Time, kthayer@pacifier.
> > com
> > > writes:
> > >
> > > > John, I don't have time to do this, so I'll have to ask you to tell me
> > > > what you think I would get. Are you saying that you've done the
> Demachy
> > > > method using this kind of sizing and found that it worked the way
> > > > Demachy and Maskell describe?
> > > > Katharine
> > > ..........................
> > > Katherine,
> > > Yes! However, I too am very busy, at present, and do not
> have
> > > time to answer your question in any further depth. When you do get time
> > please
> > > do try it.
> >
> > 10% gelatin, 5% cornstarch, is there any hardener at all?
>
> ............................................
> Katherine, No hardener! Glad youre finding time.
> Bye bye.

No, I'm not finding time, I'm just curious, sorry.

It seems to me that what happens, at least in my own experiment with the
method, is that the dichromate reacts with either the internal or the
external size in the paper, maybe even more than with the gum that is
added on top. And this would be even much more true of an unhardened
surface size, I would think. So you get a dichromate-size image with a
little dichromate-gum-pigment on top to give it color, and all the gum
and pigment above it goes away.

  But at any rate I'm not terribly interested in following up with it,
because my only interest was to find out if there was some sort of
principle underlying it that could be used to explain something about
the dichromated colloid process in general, as my chemist friend was
assuming. Since it's clear that the effect is probably only specific to
a few paper-size combinations, it doesn't interest me at all, because
it's obvious that nothing about it is generally applicable.
Katharine

At any rate,
Received on Mon Apr 11 18:54:12 2005