Re: aguatint screens and photogravure screens

[Gary Beasley <beasleyglb@mindspring.com>]

At 01:58 PM 8/16/01 +0200, you wrote:
> > At 01:19 PM 8/12/01 +0200, you wrote:
> > > > I work with photolithography on a daily basis
> > > > so you should check the details on that gravure screen to find out
> > > > exactly what it is.
> > >
> > >Gary, could you explain in a few sentences what photolithography is?
> > >I have seen a print recently and wondered ever since.
> >
> > Photolithography is the most common process printers use in their
> > printing methods. The name litho  comes from the fact the process was
> > first done with a smooth stone as the image bearing surface (probably
> > a limestone). A greasy image was drawn onto it then the stone was
> > dampened and a greasy ink applied. The damp stone repelled the ink and
> > the grease image attracted it. Then a clean sheet of paper was pressed
> > onto the surface that picked up the ink resulting in a reverse of the
> > stones image. If done right its pretty high quality.
>
>Thanks Gary. Is there a process by which one can print a continuous tone
>(no half-tone) photo from such a lithographic stone?
>
>Brahma

The military tried that out and yes you can do it but it's very tricky work 
from what I hear. I've seen the results which didn't look too bad but don't 
know the details of it or even what they called that specific process.