U of S | Mailing List Archive | alt-photo-process-l | printing gum on glass

printing gum on glass

Quiet list this summer! Is no one doing photography???

Tomorrow on my 4th of 6 trips this summer (gasp); onto APIS.  No rest for
the weary.  Hope to see some of you there. In between trips I work on myth

Anyone print gum on glass?  I was working on an example to disprove the myth
that printing on glass produces no midtones, a myth that seems to be
repeated in books and is based on the assumption that the surface is sooo
smooth with no bumps that it will not hold the midtones.

Well the total image printed as I suspected.  But I noticed an odd
thing--the top layer of gum when it hit the water sloughed off in pieces,
revealing the complete image below it.  I wanted to see if anyone else had
noticed this or even printed an image on glass (probably not), and if, those
of you carbon printers (Sandy?) have said unequivocally that your tissue
hardens from top down, correct?

This example is not refuting that theory--because the top slough off layer
was hardened.  But I still am working on the solarplate statement, perhaps
ultimately not at all related, that solarplate hardens from the bottom up
and why that might be different than gum.  I do not know what the
photosensitive substance is in solarplate but the polymer being hardened is
either nylon or pva and perhaps other things, and pva is also used in
dichromate processes.


Christina Z. Anderson
Assistant Professor, Photo Option Coordinator
Montana State University, VCB 220
Box 173350
Bozeman Montana 59718