Acid-free papers are manufactured in an alkaline environment, which prevents the internal chemical deterioration of the paper over time. The addition of calcium carbonate as a buffer also makes the paper resistant to the effects of an external acidic environment.
Basis weight is the weight of 500 sheets (one ream) in a standard basic size. For example, the standard basic size for text papers is 25" x 38." A ream of basis 70 text sheets in that size weighs 70 lbs.
Originally a term applied to cotton-content paper used for printing bonds and legal documents and distinguished by strength, performance and durability. Bond paper may now be made from either cotton, chemical wood pulp or a combination of the two. Today, writing, digital and cut size papers are often identified with the bond scale.
General term for papers suitable for the graphic arts; may be coated or uncoated. Book is Equivalent in weight to text papers.
Brightness is measured as the percentage of light in a narrow spectral range reflected from the surface of a sheet of paper. It is not necessarily related to color or whiteness. A paper with a brightness of 98 (like Mohawk Navajo) is an extremely bright sheet with almost all light being reflected back to the viewer. Bright white papers illuminate transparent printing inks, giving cleaner, crisper color and contrasty blacks.
Caliper is a measure of paper thickness expressed in thousandths of an inch. The micrometer is used to measure caliper.
High-gloss coated paper manufactured by casting the coating paper against a highly polished, heated steel drum.
Made with a surface coating, which allows for maximum smoothness and ink holdout in the printing process. Coated papers are available in a range of finishes from dull to matte and gloss.
Cover paper is a heavyweight coated or uncoated paper with good folding characteristics. Their diverse uses include folders, booklet covers, brochures and pamphlets.
Produced in hand-paper-making by drainage under a wooden frame surrounding the hand mold. The rough edges on hand-made and some machine-made papers were originally considered an imperfection. The deckle edge came back in fashion with the handcraft revival in the last decade of the 19th century.
Papers designed for the specific processes of the emerging digital printing technologies. Unlike traditional offset printing, the digital environment is centered in quick turn-arounds, short runs and the ability to vary printed information within the run. There are papers available that are designed for both digital and offset operations and come in both sheets and rolls.
Stiff, durable cover papers produced by laminating together two pieces of equal-weight paper. The resulting sheet is heavy and strong, with excellent printing and folding characteristics.
Woven textile, originally wool but now usually synthetic, used to carry the web while moisture is pressed from it. While on the paper machine, the felt acts as a support for the paper web. Felts, if they are rough, can impart a felt finish to the papers.
Refers to the uniformity and distribution of fibers within a sheet of paper. In a well formed sheet, solid ink coverage will go down smoothly. A poorly formed sheet will exhibit a mottled appearance when printed. Formation can be checked by holding the paper up to a light source: A well formed sheet appears uniform, while in a poorly formed sheet the fibers appear as clumps, giving it a cloudy look.
FSC is a certification system that provides internationally recognized standard-setting, trademark assurance and accreditation services to companies, organizations, and communities interested in responsible forestry.
Genuine Felt Finish
A finish applied to paper by means of marking felts while the paper web is still very wet. These felts impart their distinctive textures by gently rearranging the paper fibers. This creates a soft, resilient, textured surface suitable for printing and relief operations.
As the paper web is carried forward on the machine, the majority of fibers orient themselves in the machine direction. When the web of paper sheeted, the sheets will be grain long (fibers that follow the long side of the sheet) or grain short (they follow the short side). Grain direction should be considered during the design process for best results during printing, folding and converting.
A characteristic of paper related to its capacity to keep ink sitting on its surface rather than absorbing into the sheet. Better ink holdout produces sharper printed images.
A linear pattern which is applied by dandy roll while the paper is still very wet, to mimic the effect of some hand-made papers. The laid dandy roll is comprised or wires that run parallel to the roll's axis (laid lines) and chain lines, which connect the laid lines and run in the grain direction.
Very smooth, low-moisture papers manufactured in cut sizes for laser printers and office duplicating equipment. Low moisture prevents paper curling from high heat in laser printers. Note: If your job is designed to run through a laser printer, you should specify laser-compatible offset inks.
One of the many textured effects that is produced by embossing a web of paper with a patterned steel roll. Embossing takes place off this machine as another operation.
Machine Felt Finish
Rubber marking rolls apply a felt-type finish to paper right before the dryer section. This technique yields a softer surface than embossing and better bulk. The surface is slightly harder than with a genuine felt finish. Though less natural in fell, a machine-felt texture is more economical and provides greater ink holdout because of its compact surface.
Mohawk Laser Guarantee
Papers bearing the Mohawk laser guarantee are guaranteed to perform in your laser printer, copier or plain paper fax machine within the limits outlined by your equipment manufacturer.
Uncoated paper designed for use in offset lithography. Important properties include good internal bonding, high surface strength, dimensional stability, lack of curl and freedom from foreign surface material.
Measure of the percentage of light passage through a sheet of paper. The more opaque a paper is, the less show-through there will be from printing on the sheet below. Basis weight, brightness, type of fibers, fillers, coatings and formation all influence opacity. Generally, opacity and brightness are inversely related to each other: The brighter the paper, the less opaque. Other factors that affect opacity are bulk, surface smoothness and shade.
Papers that contain postconsumer fiver can currently be called recycled. The Federal Executive Order calls for a 30% postconsumer fiber minimum for uncoated papers and a 15% postconsumer fiver minimum for coated papers.
The Sustainable Forestry InitiativeŽ label is a sign you are buying wood and paper products from well-managed forests, backed by a rigorous, third-party certification audit.
A surface quality of a sheet of paper, related to the flatness of the sheet. This characteristic of smoothness affects ink receptivity. Smoothness is measured on the Sheffield scale. A higher value typically indicates a rougher sheet-for example, coated paper may have a smoothness of 10-30, vellum offset from 200-250.
Text and Cover Papers
A class of high-quality uncoated papers in a wide variety of colors and textures. Text is usually made with a marching or coordinating cover.
Natural or machine finish, like antique or eggshell.
Design formed in fine wire or in low-relief metal castings and sewn onto the dandy roll. The resulting thick and thin areas make the watermark slightly more translucent than the rest of the sheet. Watermarks were historically used to convey a sense of quality in letterhead papers.
The side of the sheet that rests on the paper machine wire as it moves through the wet end, as distinguished from the felt or top side.
Suitable for pen and ink, pencil, laser printing or offset printing. Writing grades are designed for letterheads, corporate identity programs and office copiers.