Oh, I have (he said, somewhat abashed) when I didn't put on ENOUGH
sensitizer, and tried to compensate by over-exposing the image. What a
mess.
With cyanotypes, at least in my limited experience, I've found that
a more generous coating -- even two coats -- will yield a richer range of
tones, even from relatively thin negatives. (I use laserprinted
transparencies). Personally, I prefer a nice rag Arches engraving paper,
but too much sensistizer will soak too far into the fibres of the paper and
make it tough to wash later (at least, without washing away the image) so I
DRY the sensitizer with a hot hair dryer as soon as I've coated the page.
This keeps the sensitizer closer to the surface of the paper.
As they say, your mileage may vary.
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Kevin Crombie e-mail: kcrombie@montreal.com
387 rue Villeneuve est voice: (514) 849-7601
Montreal, P.Q. H2T 1M1