Paper may be defined in terms of its use. Each grade serves a purpose, usually suggested by its grade name. Some of the most common classifications of printed papers are bond, coated, text, cover, book, offset, index, label, tag and newsprint. The size shows in parentheses is the basic size for that grade.
Bond (17x22) papers are commonly used for letters and business forms. They have surfaces which accept ink readily from a pen or typewriter and can be easily erased. Most letterheads and business forms are a standard 8-1/2 x 11 size
Coated (25 x 38) papers are sued when high printing quality is desired because of its greater surface smoothness and uniform ink receptivity. There are many kinds: cast coated, gloss coated, dull coated, machine coated, coated one and two sides, ets. Coated papers are classified within a set of grade levels (premium to No.5) based on paper brightness. This classification, established by the American Forest and Paper Association (AFPA), defines the grade levels as follows:
Grade Level: Brightness
Premium: 88 and above
No. 1: 85 – 87.9
No. 2: 83 – 84.9
No. 3: 79 – 82.0
No. 4: 73 – 78.9
No. 5: 72.9 and above.
The AFPA allows a paper manufacturer to classify a coated brand with the highest-grade level that its brightness meets or at any level below. In today’s market, most grades exceed the brightness range specified in the category; e.g., at 88 brightness, International Paper’s Savvy grade qualifies as a Premium paper; however, it is promoted and reported as a No. 2
Text (25x38) papers are noted for their interesting textures and attractive colors. They enjoy frequent use for announcements, booklets and brochures. Most text papers are treated with a sizing to make them more resistant to water penetration and easier to print by offset lithography.
Book (25 x 38) papers are used for trade and textbooks as well as general printing. They are less expensive than text papers, and are made in antique or smooth finishes. Book papers have a wider range of weights and bulk than text papers so it is possible to secure almost any desired bulking.
Offset (25 x 38) papers are similar to the coated and uncoated book paper used for letter press printing except that sizing is added to resist the slight moisture present in offset printing, and the surface is treated to resist picking.
Cover (20 x 26) papers complement coated and text papers in heavier weights and matching colors for use as covers on booklets, etc. Papers are also made for cover purposes only Many special surface textures are available, with finishes ranging from antique to smooth. Special characteristics of cover papers including dimensional stability, durability, uniform printing surface, good scoring, folding, embossing and die cutting qualities. It is a useful rule of thumb that cover stock of the same basis weight as text papers has about twice the thickness.
Index (22.5 x 35 and 25.5 x 30.5) papers have two outstanding characteristics -- stiffness and receptivity to writing ink. Index is commonly used whenever an inexpensive stiff paper is required. It is available in both smooth and vellum finish.
Tag (24 x 36) is a utility sheet ranging in weight from 100 to 250 pounds for manufacturing pulp, and various types of waste papers. Tag board is sometimes tinted and colored on one or both sides. Tag stock has good bending or folding qualities, suitable bursting and tensile strength, good tearing and water resistance, and a surface adaptable to printing, stamping or writing.
Bristol (22.5 x 28.5) is one of the board grades, with a softer surface than index or tax, making it ideal for high-speed folding, embossing or stamping. It is an economical substitute for cotton fiber stocks, is very receptive to ink and has good snap and resilience.
Newsprint (24 x 36) is used in printing newspapers. Furnish is chiefly groundwood pulp, with some chemical pulp. It is made in basis weights from 28 to 35 pounds, with 30-pound used extensively.
Lightweight papers such as manifold, onionskin and Bible paper are specialty grades that have been produced for years.
Digital papers have been designed for use in digital printing equipment. The term "digital" implies digital date; thus, most output devices can include ink-jet printers (wide and narrow), laser copies and printers, high-speed digital presses such as the Xeikon, Indigo, NexPress and Xerox Docutec equipment. What makes digital papers special is that they have been made specifically to holdout ink from the ink-jet printer and resist puckering or curl, while giving good ink print density. In laser systems, digital papers resist heat, thus eliminating curl when passing through the fuser unit of laser systems. They also hold good electrical charge for excellent toner adhesion in the same laser systems.
(From PocketPal by International Paper)
Department of Communication, Seton Hall University