Lexus on an exposure unit, that'd make a good pic.
Anyhow,
I'm not sure how much you know Fleetee, so please don't take offence.
If I recall, my explanations to the trainees went something like this..
Very, very, generally speaking regarding mesh counts.
For exposing linework, you could use 80 mesh if you felt so inclined, without losing too much detail.
Once you get into halftones, finer mesh is required.
For example, I used artwork ripped at 40lpi, exposed on 150-160 mesh everyday for years.
( that was just our 'always works' set it and forget it )
If I ripped the artwork at say, 55lpi I couldn't hold certain ranges, so a finer mesh was required.
To keep it simple, think of mesh in ink thickness terms, and halftone exposure ability.
But, as almost everyone has mentioned, you NEED a vacuum blanket, or you will chase your tail
with workarounds and frustration all day long ( I know, I have ), unless you're doing the real simple stuff.
And of course, all those important variables with bulbs, emulsion, coating, etc, ad nauseum.
Many folks on here with tons of knowledge on the science of it all.
Hope that helps.
Cheers.
