> E THEISEN schrieb:
>
> > The
> > picture frame is a new and super idea and will eliminate part of the coating
> > challenge. Good on ya. Ernie Theisen
>
> Not really new... but good anyway. I remember having seen it as a 19th
> century illustration (in Luis' book?)
> Klaus Pollmeier
A couple days ago, I tried cutting an opening in a piece of mat board to
to act as a dam to contain the gelatin. I soaked this with the poster
board that I am using as the tissue support. Squeeggeeing the poster board
on a glass plate, and then the mat board window on top of this made it
possible to make very well defined pieces of transfer tissue with little
mess.
The thickness of the matte board works as a depth gauge. However, pouring
a known quantity of gelatin solution into a frame would achieve the same
result. The use of a frame with the thickness of desired film does allow
a doctor blade to be drawn over the poured gelatin to help remove bubbles
though. I thought I'd see about finding a thin rubber mat to make a
reuseable, easilly cleaned casting frame.
Klaus' approach of "inverse casting" where he pours the gelatin on a
smooth surface and puts the paper support on the top would most likely
minimize the occurance of flaws due to bubbles and airborn particulates.
Unfortunately, the one time I tried this, I used a piece of window glass
to which the gelatin layer decided to stick. The casting surface must be
very clean to prevent the gelatin from sticking. The gelatin might be
less likely to stick to the plexiglass? I'm also wondering if waxing the
glass or plexi would help prevent sticking? Would a wax film possibly
introduce a new problem?
- Wayde
(wallen@boulder.nist.gov)