GLASSINE - A smooth dense semi-transparent paper. Sometimes used as window patch material, but losing popularity compared to the new poly- styrene materials which are more transparent and less sensitive to moisture. Glassine is biodegradable and recyclable.

GRAIN - Direction in which most of the fibers lie in a finished sheet of paper. Paper folds more easily with the grain. It offers greater resistance to being torn across the grain, and demonstrates greater tensile strength in the direction of the grain.

GRIPPER EDGE - The leading edge of paper as it passes through a printing press or folding machine. No printing can take place on 3/8" of the paper on the gripper edge. Referred to as a “common edge” when jogging a stack of paper.

GUIDE EDGE - The side of a printed sheet from which copy registers left to right. This is the second “common edge.”

GUIDE MARKS - A method of using cross line marks on the offset press plate to indicate trim, centering of the sheet, centering of the plate.

GUM - An adhesive made with a plant base to seal paper envelopes. Some gums take moisture to seal, others such as latex gums will adhere to themselves.

GUM SEEPAGE - A term used to describe a manufacturing problem caused by an excessive application of back gum resulting in consecutive envelopes sticking together at the seam or the inside pocket of the envelope being stuck closed at the seam(s).