Printing Paper Terminology
Paper terminology can seem very confusing to someone who doesn’t work with commercial printing papers every day. In this section, we will try to explain some of the terms up front, so the information that follows will be more understandable.
Aqueous Coating: A water-based coating that is applied to a sheet after it is printed to improve printed appearance and durability.
Basis Weight (or “Weight”): The weight in pounds of 500 sheets of paper in that paper’s basic sheet size, which for our text weight paper is 25 inches by 38 inches. The basic sheet size for our cover weight paper is 20 inches by 26 inches.
Brightness: The reflectance or brilliance of a paper sheet. Higher brightness usually results in a better printed appearance of ink colors.
C1S or C2S: C1S = “Coated 1 Side”, C2S = “Coated 2 sides”, to describe what side(s) paper is coated on.
Caliper: The thickness of paper expressed in thousands of an inch.
Coated Paper: Paper that has been manufactured with a surface coating that improves smoothness, durability, and ink receptivity. Coatings may be glossy, dull, or somewhere in between.
Cover Weight : A heavier paper having the caliper, basis weight, and durability required for booklet covers.
Dimensional Stability: The degree to which a paper will maintain its size and shape when subjected to changes in temperature, moisture content, and relative humidity.
Fiber: The slender, thread-like cellulose structures that form a sheet of paper.
Filler: A generic term to describe the non-oxidizing clays or minerals added to the pulp to improve paper density.
Finish: A complex property of paper related to its smoothness, and other surface properties.
Formation: The arrangement of fibers in a sheet of paper; can be seen by holding it up to a light source.
Grain: Direction of paper fibers, long grain describes fibers running parallel to the longest side of a sheet, and short grain running parallel to the short side of a sheet. Folding results for some products are dependent on grain direction.
Grammage: The weight in grams of a square meter of a particular type of paper, a good comparative measure because it does not vary with sheet size. Often expressed as “GSM”, it is a measure of density.
Index Paper: A heavyweight stock, with a smooth finished used for products such as postcards, business cards, or any forms needing extra durability.
Machine-Made Paper: Paper made on a very rapid running machine called a "Fourdrinier," producing consistent mass quantities of sheets or rolls of paper.
Offset Paper: Paper that has been manufactured with properties that make the paper suitable for offset printing.
Opacity: A property of paper measuring the amount of light that can pass through. Higher opacity results in less show-through of images from the opposite side of the paper sheet.
Point: A measure used in printing equal to about 1/72 of an inch commonly used for type size. A point in paper measurement (“caliper”) is equal to 1/1000 of an inch.
Post-Consumer Recycled: Recycled paper that is manufactured from paper that has already been used by consumers. Pre-consumer recycled typically uses waste from the paper manufacturing process.
Pulp: Cellulose plant fiber cleaned and beaten into a wet mixture used to form sheets of paper.
Text Weight: A lighter weight paper that is appropriate for the inner pages (“text”) of a booklet, and is commonly used for printing brochures and flyers.
Uncoated Paper: Paper that has been manufactured without the use of coating materials.
Yield: A measure of the square inches of paper per pound.