They should know what they contribute to the process, but should have enough peripheral vision to see what else goes into the ad. Set up a quality board - Showing good work reinforces good behavior. Try to be as positive as possible. The pressroom staff should know fundamentals of the CMYK color model. If an advertiser uses an outside agency to create the ad, then they need more information than line screen and density.
Agencies don t calibrate their software and scanners for newspaper work.
Commercial color separations differ greatly from newspaper separations.