Katharine Thayer wrote:
>
>
> When I was experimenting with exposing unpigmented dichromated gum on
> mylar for research purposes, I found that printing the way I ordinarily
> print, the hardened and dried gum was absolutely crystal clear,
> colorless. But if I cleared the hardened gum, then it turned light blue.
> And if I printed to the point of dichromate stain and then cleared it,
> then the cleared hardened gum was REALLY blue. The blue color was not
> eliminated by a water bath after the clearing step. So that experience
> has convinced me that I get the very cleanest gum by not clearing.
unless obvious stain necessitates the clearing, of course.
kt
Received on Mon Aug 8 22:29:44 2005
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