Digital BW, The Print

> Can you tell me what the screen-printing process is?

Screen-printing is another (relatively unused) term for half-tone 
printing. This is the basic method of printing used in almost all 
printed materials these days - newspapers, books, magazines. In 
essence the tones are created by arranging tiny dots in regular rows 
and columns on a page. The smaller the rows and columns (think graph 
paper here) the finer the line screen. Regardless of the size of the 
line-screen, the more a dot fills its little square area (really its 
usually round or oval, but let's not get too technical) the darker 
the area of the image.
Therefore, a 200 line screen contains 200 dots per lineal inch left 
to right and also 200 dots per inch top to bottom. For reference, 
daily newspapers usually print about 85 lines per inch. USA Today 
prints at 100 lines per inch. Magazines are usually 133-150 lines per 
inch. LensWork prints at 200 lines per inch. And the very best 
photography books out there are at 300 lines per inch. This is the 
functional limit of printing presses. Our LensWork Special Editions 
use an even higher screen - 425-lines per inch. Image setters can 
create this film, but printing presses can't print it so most people 
in the industry are not aware that their image setter will go that 
high!
Finally, a 425-line screen will represent highlight areas with a 1% 
dot. That means the smallest dots in the finest highlights will be 
0.0000235 inches in diameter. This is far finer than the size of a 
stochastic dot, and that is why we don't use Dan Burkholder's method 
of stochasitic screening for printing on gelatin silver.
Does this help? I am new to this forum, so I apologize if this is all 
old news to all of you.
Brooks Jensen, Editor
LensWork Publishing