Definitions - Paper Terminology

Acid Papers Traditionally, most papers were acidic, although by now the majority of mills have converted to the alkaline papermaking process. Acid papers rapidly become yellow and brittle with age. (Unlike alkaline paper, which can last up to 40 times longer.) They are made from chemical pulp and contain clay or titanium dioxide fillers with a pH of 6, 7, or less.

Alkaline Papers An alkaline paper has a pH of 7.5 to 10, and contains calcium carbonate in place of conventional fillers. Higher-grade alkaline papers use precipitated calcium carbonate. The chief advantage of alkaline papers is that they retain their crispness, suppleness, strength, and color far longer. That makes them particularly suitable for important documents, books, and other publications.

Basis Weight The standard way of categorizing paper. Although sheets are sold in different sizes, a basic size for each category is used to calculate the basis weight. For example, a basic size of 17" x 22" is used to calculate the basis weight and price of bond paper. Since the basis weight is calculated on 500 sheets, a label that reads "17 x 22 - 20 lb.," means that 500 sheets of 17" x 22" paper has a basis weight of 20 lbs.

Bond Papers The typical office paper. A durable multipurpose sheet that withstands repeated folding, bond is used for correspondence, photocopying, typing, and writing. Increasingly, it's manufactured to laser printer specifications. Bond may contain cotton, chemical pulp, or both. Basic size: 17" x 22". Basis weights: 20 lb to 28 lb.

Bristol A light cardboard made from chemical pulp, available in a variety of colors and textures. Bristol's strength and durability make it ideal for high-speed folding, stamping and embossing. Particularly suitable for pieces that will be handled frequently. Basic size: 22 1/2" x 28 1/2". Basis weights: 57 lb. To 80 lb.

Chlorine-Free Papers Standards haven't been set for North America, so the designation "chlorine-free paper" usually means one of three things:

• Elemental Chlorine-Free (ECF): In place of pure chlorine, safer chlorine compounds such as chlorine dioxide are used for bleaching. This is the most common form of bleaching in North America.
• Processed Chlorine-Free (PCF): This is a term reserved for recycled-content papers. If the paper contains some virgin fiber, that fiber is totally chlorine-free. The recycled portion, including the post-consumer fiber, has not been rebleached with chlorine-containing compounds.
• Total Chlorine-Free (TCF): Absolutely no chlorine or chlorine compounds are used in the bleaching process.

Cover Papers Matched with text papers, cover papers are heavier and stiffer to protect their contents. They must exhibit all the aesthetic characteristics of text papers: attractive colors, textures, and finishes. May be used for invitation cards, business cards, and business reply cards. Basic size: 20" x 26". Basis weights: 50 lb. To 80 lb.

Film Coat Refers to uncoated grades which have been surface treated with a slight coating to improve their printability and ink retention.

Index Papers A stiff sheet that's particularly receptive to ink. A good choice for all types of printing, serigraphy or offset lithography. Standard size: 25 1/2" c 30 1/2". Basis weights: 90 lb. To 110 lb.

Mill Waste Collected from paper mills and reintroduced into the papermaking process. Like post-commercial waste, mill waste has always been recycled. There are four types:

• Wet Broke is collected from the "wet press end" of a papermaking machine.
• Dry Broke comes from the "dry end" of the papermaking machine, and might include reel ends and trim from deckle edging.
• Pre-Commercialization Waste includes paper that's deckled on reels during sheeting operations, as well as rejects.
• Forest Residues might include whole wood chips, sawmill waste, and sawdust.

Neutral Papers Made in the same way as an acid paper, but then covered with an alkaline coat to neutralize the acid. Neutral papers have a pH between 6.8 and 7.4.

Offset Papers The most common sheet for flyers and commercial printing. Made from chemical pulp to which starch is added for better offset press performance. A separate treatment also makes this paper tear-resistant. Printers and designers can choose from a range of finishes, colors, and basis weights for web and sheet-fed presses. Basic size: 25" x 38". Basis weights: 40 lb. To 120 lb.

Opaque Papers Similar to offset papers, but with significant improvements in print fidelity, contrast, and press performance. As the name suggests, these papers also offer higher opacity and higher brightness levels, making them the first choice for projects where quality is an issue.

Permanent Papers Like alkaline papers, permanent papers last far longer - up to 400 years. However, a permanent paper offers an extra measure of protection because it meets criteria set by the American National Standards Institute (ANSI Z39.48-92). The standards require a pH of at least 7.5 reserves of precipitated calcium carbonate as protection, and a minimum level of lignin. The infinity symbol (?) denotes a permanent paper. ANSI also requires that a permanent paper meet certain conditions for resisting damage through normal use.

Post-Commercial Waste Usually found in paper converters' and printers' waste bins. It may contain unsold paper, trim from envelopes and binding, from merchants, retailers, and wholesalers. Post-commercial waste has been recycled for years.

Post-Consumer Waste This is waste that has "lived out" its life-cycle, as it were. It's been rescued from the waste bins of businesses, homes, schools, and institutions, and diverted into a papermaking plant. Post-consumer waste typically includes cardboard, newspaper, magazines, stationery and other assorted papers, and is used to produce newsprint, cardboard, and other products. However to produce a fine paper with post-consumer waste, that waste must contain only fine papers.

Recovered Waste This is Post-Consumer Waste (see above), plus trimming, old inventory, and other waste recovered from printers, paper wholesalers, and paper converters. However, it excludes waste generated from any part of the papermaking process before final manufacture.

Recycled Fiber Post-consumer and post-commercial waste finer falls under two categories:

• Non de-inked: Recycled without treatment.
• De-inked: Subjected to a series of treatments to remove inks and other contaminants.

Text Papers Designers naturally gravitate to text papers, since they offer the widest range of colors and textures. Finishes include vellum, smooth, laser, linen, or laid. Particularly suited to promotional materials, text papers are used with their color-coordinated cover counterparts for brochures, reports, and books. Basic size: 25" x 38". Basis weights: 60, 70, and 80 lb.

Unbleached Papers No bleaching process has been used during pulping. A typical example is a brown paper bag.

Virgin Papers Contains no post-consumer or post-commercial waste, but does generally contain mill waste.

Watermark A design that is imprinted in the paper while on the wet end of the papermaking machine. Offered in raised, sunken, or two-toned.

Writing Papers or Premium Stationery Often the most elegant of sheets, writing papers are typically used for letterhead or office stationery, and sometimes have 25%, 50%, or 100% cotton content. They usually have a watermark. Specifically designed for ballpoint, fountain pen, or typewriter. They usually have matching text and cover papers, and are available in laid, smooth, and laser finishes. Basic size: 17" x 22". Basis weights: 20 lb, 22 lb., and 24 lb.