To smooth the finish of paper in the final stage of paper making. The calendering process also can be used to make paper thinner.
Caliper
See Micrometer.
Coated paper
Printing paper with a surface coating that is smooth and receptive to ink, and primarily used for magazines and brochures.
Cover weight
In older paper mill jargon, cover weight is a way of measuring the thickness–and therefore weight–of thicker card material, as opposed to text weight, which measures thickness and weight of thinner papers.
Felt
The fibrous mat that rolls on top of the paper during its manufacture, while the fiber/water mix is floating on the wire. Because the felt surface supplies the texture to the top side of the paper, the top side of paper often is called the felt side. Hence, the underside of a sheet of paper often is called the wire side.
Fiber
An elongated plant cell that is the microscopic, basic ingredient in paper.
Finish
The texture of the surface of paper.
Flat card
A thick piece of paper that is cut as a single panel without a fold.
Fold-over
Any note that folds evenly in half–usually with the fold at the top.
Grain
The direction that the fibers take as paper is made.
Guillotine
An instrument, such as a paper cutter, similar in action to a guillotine.
Kraft paper
A tough brown paper used for wrapping or packing. Most paper bags are made from kraft paper.
Laid paper
A pattern showing parallel wire marks that emerge on the paper surface during manufacture. This pattern appears as a fine striated or corduroy effect on the paper surface.
Micrometer
A tool that measures the thickness of paper in 1/1000-inch increments. This tool also is known as a caliper. The measure itself is sometimes called "the caliper." For instance, one might say: The caliper of the paper is 5/1000-inch. The most common thickness of paper is from 5/1000-inch to 10/1000-inch.
Paper
A felted sheet, usually made from vegetable fibers, laid down on a fine screen via a flow of water.
Paperboard
A flat, somewhat coarse material made from wood pulp–similar to paper but thicker–and usually used to make light-duty boxes such as shoe boxes or gift boxes.
Paper mill
A factory that manufactures paper.
pH
The measurement of acidity in paper chemistry. Most papers now are made with a neutral pH measurement so they are balanced between acid and alkaline. This is more desirable for water treatment in the paper mill and its immediate environment.
Pulp
The mixture of fibers and water from which paper is made.
Sheffield
The name of a standard laboratory test that measures the smoothness of paper finish.
Uncoated paper
Regular paper used for stationery, books, and newspapers.
Ream
A ream is 500 sheets of paper.
Side seam
The left or right side flap of an envelope where gum is applied to bind the side flap to the back flap of the envelope.
Vellum
In modern usage, the term represents a strong, cream-colored paper. Originally, in ancient times, vellum was the treated skin of a calf, used as a writing material.
Watermark
A marking in paper resulting from differences in thickness.
Wove paper
Paper made with a revolving roller covered with a pattern that produces no lines running across the grain of the paper. The finish thus produced looks like fine woven cloth. (Compare with laid paper.)
Stock
A term commonly substituted for the word paper.
Wire
The wire mesh used at the "wet" end of the paper-making machine. The wire determines the finished texture of the paper, and also provides the watermark design in fine watermarked papers.