Well I'm sure I'm right this time, probably.

The need for crop marks has long gone. Back in the old tape-up days with double
sided boards, they had a purpose. Artwork was supplied from camera reduced
positives/negatives, and some sort of fab information was usually supplied along
with the film. That seems like centuries ago. The boards were sheared before
the film was overlayed to expose the copper.

But with todays CAD systems, the need is gone. The fab shops remove any crop
marks when they panelize the gerber files. They establish their own tooling 
holes for quality control.    Why then do we still see them on the artwork?

Isn't this just another example of how slow the industry is to change?

How many times have you heard the old "This is the way we do it" comment.
Very rarely does it include a "why". It's even rarer for someone to admit that
a change is needed in the way we design and produce artwork.

We can allmost say the same thing about moires. They allow us to line-up the
film for artwork inspection, but they to are not used in the fab process. The
moires like the crop marks are removed before the gerbers go through the step
and repeat (panelize) process. Fab shops use their own tooling holes as a means
of registration.



Well I quess I just missed another question on my IPC exam!

Al Slagle