G
GHOSTING
A faint image on a printed sheet appearing in an area where it wasn’t intended. Mechanical ghosting develops a repeat image on the same side of the sheet due to a press condition, such as blanket problems and ink starvation. Chemical ghosting develops as an image on the back side of a sheet, transferred from the front of the sheet below and occurs during the drying of the ink on paper.
GLOSS
Gloss can refer to the reflectivity of paper itself or of the printed result on it. Gloss of paper is calculated by using a Gardner gloss meter, which measures reflected light at an angle of 75°, and is expressed in Gardner gloss units – the higher the number, the glossier the paper surface.
GRAIN DIRECTION
A term applied to the machine direction of papers or boards, opposite to the cross direction.
GRAMMAGE
The term used to denote the weight of paper or board; the measurement used is the weight of a single sheet of one square meter, presented as grams per square meter (g/m2).
GREASEPROOF PAPER
Paper free of mechanical pulp, highly resistant to grease. Mainly used for the wrapping of greasy products.
GREEN PAPER
Unripe paper that has not been conditioned or had the opportunity to mature naturally.
GRIPPER
Metal finger like clamps that grab the paper to pull it through the press as the sheet is being printed.
GRIPPER ALLOWANCE
The edge of paper along the gripper edge of the sheet held by the grippers and that, therefore, cannot be printed.
GRIPPER EDGE
The edge of the sheet presented to the gripper. The edge of the plate that is fitted to the leading clamp of the cylinder.
GROUNDWOOD PULP
Paper pulp produced by mechanically grinding wood logs making a weak, acidic paper that discolors upon exposure to light.
