<dan.c.quinn@[EMAIL PROTECTED]
> wrote in message
news:cb38f68c-88c7-4304-9b60-600350212ea2@[EMAIL PROTECTED]
Mar 5, 5:19 am, Richard Knoppow wrote:
>
>The differential drying gotten with a screen is also the
>reason
> blotter books and rolls have a non-permeable sheet, waxed
> paper in the very old ones, interleaved with the blotters.
> The idea is to put the emulsion against the sheet so
> that the drying takes place mostly from the sup****t
> side minimizing curling. Richard Knoppow
>
Wondered about those "non-permeable" sheets. My blotter
book was set aside years ago in favor of a corrugated board
stack dryer. Although the prints do come out of the dryer
with
nothing more than a hint of emulsion side curl they do over
time, unweighted, develop some more emulsion side curl.
As it is the stack is built by alternating layers of board,
hydrophobic sheets, and prints; a same sheeting each
side of the prints. Perhaps I should be using a less
permeable sheet emulsion side for long term
flatter prints. Dan
Worth a try. The idea of these things, especially the
blotter rolls, is that there is some air circulation at the
back side of the blotters allowing faster drying. Kodak used
to make a print dryer using corrugated blotter rolls with a
blower.
The same principle works for flattening prints using a
dry mounting press. The print is put in the press with
either several sheets of pre-dryed "kraft" paper on the
sup****t side or a sheet of blotter paper, also pre-dryed in
the press there. The emulsion side is covered by release
tissue. The print is put into the press and heated for a
minute or two and then the entire sandwich of release
tissue, print, and backup paper, is placed under a flat
weight to cool. I've found this method to be very effective
for fiber based prints and, once flattened this way, the
prints seem to stay flat regardless of temperature or
humidity.
It does not work for RC of course, because the base does
not absorb or loose water. BTW, RC prints seem to curl right
up when the RH get really low, as it does here sometimes.
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Richard Knoppow
Los Angeles, CA, USA
dickburk@[EMAIL PROTECTED]
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