Press Types, Sizes and Features Format or Paper
Offset presses are either sheetfed or web. Paper feeding into a web press come off a roll and is cut into sheets after printing. Paper feeding in to a sheetfed has already been cut.
Press size is identified according to the widest sheet or roll of paper the machine and handle. A 40-inch press can run a sheet or roll up to 40 inches wide. Small sheetfed press print sheets 18 inches or less. That size includes most presses at quick and in-plant shops whose maximum is 11″ x 17 or A3, and it is good for stationary, fliers, newsletters and forms.
Small presses run solids ink on uncoated paper 90% of the time, but many are capable of much more. Large sheetfed presses can run stock from 12″ x 18″ up to 55″ x 78″ even though few printers have machines larges than 40″. However, most commercial printers consider 19″ x 25″ and 25″ x 38″ sheet sizes versatile enough to handle almost any job.Large presses prove highly efficient for many jobs because they gang images.
The circumference of the impression cylinder and a web press is its cutoff and determines the maximum length of the images ares. A web press with a 23-inch cutoff and running a roll 35″ wide would print images imposed similarly to a sheetfed press running 23″ x 35″ stock. On the most web presses, cutoff is not adjustable. Knowing cutoffs for specific presses helps plan for efficient use of paper.