Quote Originally Posted by holmburgers View Post
Here's a picture of one of the screens... http://www.imcclains.com/catalog/blo...ntscreens.html

Sounds promising.

I don't quite understand the double-exposure; I thought that usually they were exposed simultaneously, but even this seems fuzzy to me, as in, how does that create half-tone from continuous tone?
"Aquatint" screens are a replacement for classic technique of using rosin powder in a "dust box" with copperplate etching. Tones are reproduced by means of the ink held in the etched areas - depth and size of the etch plus the viscosity of the ink used are the major determinants of the tonal range produced.

Think of the double exposure somewhat akin to getting the image 'off the toe'.