One piece of advice that our Pressroom Manager always gives to our customers is to coat and protect all jobs that print on dull or matte sheets. His reasoning? Dull and Matte sheets tend to mark and offset when used in combination with heavy ink coverage and large solids.
Paper is much like a sponge, soaking up liquids that come into contact with it. With dull, matte, and uncoated jobs, ink absorbs more easily into the paper. As the sheet is going through the press, scuffing on the fresh ink can occur if there is something in the printer that hits the sheet. The thicker the stock, the more of a chance there is of this happening.
Offsetting occurs when the weight of paper with wet ink causes the image to transfer to the other side of the paper. By coating the job, this nearly eliminates the chance of offsetting happening.
Short on time? Coating also helps speed up your printing job as it traps the ink underneath and makes it dry to the touch. Also take into consideration the bindery. Does your job score, die cut or saddlestitch? If so, it is likely that you need to add aqueous coating or varnish to your job to protect it as it goes through these additional bindery functions.
