padded forms Set of forms joined together by padding compound (flexible glue). pages per inch (ppi) The number of papers that can be continued within a one inch thick stack of sheets of paper. A term used frequently in book production. pallet Construction made of light wood or paperboard on which paper or other materials are packed for shipment. Pallets are usually not reusable. They are used to facilitate the movement of paper in storage or transit by means of motorized lift trucks. panochromatic shots Images that are reproduced in one color by using pan film which allows separation of color, especially red, from original copy. Paper Distribution Council Members are executives of manufacturers and distributors of printing and writing papers and/or industrial papers concerned with the problems of wholesale paper distribution. papeterie A writing paper used for greeting cards and stationery, which is distinctive from regular stock in that special watermarks and embossing may be used. Has ability to fold without cracking. parchment Originally a writing substrate using a processed skin from calfs, goats, sheep and other animals. Today, the term is ambiguous. In writing paper, the sheet is produced with a finish to resemble the processed animal skins of old. However, vegetable parchment is an entirely different products. It is a packing paper that resembles glassine paper. (See vegetable parchment). paris white Pure form of calcium carbonate. paste-up Camera-ready art work properly positioned on one page for a print order. Also called a mechanical. pasted Those grades of paper or paperboard made up of layers pasted together. The process is an off-machine operation used to combine sheets of the same or different papers into a single thickness. pasted blanks Heavyweight stocks, pasted together, that range from 15 to 48 points in thickness. Some grades are coated, some uncoated. Some are made in colors. paster Unit that pastes two or more sheets to produce pasted paper grades. It can be produced in continuous rolls or separate sheets. pasting Process by which two or more sheets of paper are united by means of an adhesive. Paper can be pasted together directly off the reel or in the web by using a roll machine or in sheets by a sheet-pasting machine. patch mark Watermark made by sewing a patch on a mold of a cylinder machine or on a dandy roll of a Fourdrinier machine. patch washering Reinforcing a hole with a glued-on heavy paper washer. Examples--shipping tags, string-and-button envelopes. patent base Steel or magnesium base on which electrotypes are mounted using clamps or hooks. patent coated Board that is lined on one or both sides with white fibers to improve the surface. Such board is manufactured on a cylinder machine. pattern carbon Carbon paper that has its coating applied in a special way. Pattern coating has nothing to do with the web direction and is applied by a process more akin to printing than coating. Sometimes known as spot carbon. pattern paper Strong paper used by designers and tailors for making patterns. Thickness ranges from 0.007 to 0.034 of an inch. pattern tissue Thin, high-tear paper used to make dress patterns. Basic size: 24" x 36"/500 sheets. Basis weight: 7.5 to 8 lbs. in sheets and 8.5 to 9 lbs. for paper in rolls. pebbling Process applied to paper, after its manufacture, which imparts a grainy surface to finished paper. Also accomplished after printing. peeling Surface scaling on the sheet of paper. Sometimes called scuffing. per M per thousand. percent Elmendorf Tearing strength expressed in percentage points. percent Mullen Bursting strength expressed in percentage points. percent tensile Tensile strength expressed in percentage points. perfect binding Method of binding books in which all the pages are converted to single sheets. They are then held in a clamp and attached to a cover with an adhesive. perfecting press (Commonly referred to as Perfector) Press which prints both sides of the sheet of paper at the same point. On the offset press, each cylinder serves as the impression cylinder for the other. In letterpress, the press has a double cylinder. There is no transfer cylinder. The sheets of paper are taken directly from the first cylinder of the press to the second, before being turned in the press. perforating A process done during or after printing, consisting of the punching of small holes in the paper that permit the easy removal of a portion of a sheet or card. perforating rule Blade for cutting impression which can be taped to the cylinders of an offset press. perforating tape Tape used in the transmission of instructions to electronic receiving units. This tape, punched with small holes representing words and symbols that activate the machine, is made from chemical wood pulps to exact specifications. It must exhibit uniform caliper, freedom from grit, mineral filler, high tensile strength, clean perforating ability and good oil receptivity.
Basic size: 24" x 36"/500 sheets. Basis weight: 51 lb. Standard caliper is .004. It is sometimes oil impregnated. perforating wheel Slotted blade used as a press or collator to cut perforated lines parallel with the movement of the paper through the machine. permanence The ability of paper to retain, for a given period of time, its desirable properties such as color, and folding endurance. Prolonged exposure to light, humidity and extreme temperatures will adversely affect this ability. pH value Degree of acidity or alkalinity measured on a scale from 0 to 14 with 7 the neutral point. Measurement of pH is important to quality control in making paper and pigments and in the preparation of platemaking chemicals. For explanation of test to determine pH, see Chapter 6. pH control of press fountain solutions is also essential to assure maximum plate-life and uniform ink drying. photo-offset Offset printing. photocomposition Placing multiple images on a plate using a step-and-repeat camera. photolith paper Offset paper. PIA Printing Industry of America. The umbrella organization of the graphic arts industry. It is a federation of national, regional, state and city associations in the printing industry. pica Unit of measure, approximately 1/6 of an inch, used in the graphic arts. Twelve points make one pica. pick strength Bonding strength. picking Fibers in the paper which tend to pull away from the surface during the printing process. This occurs when the tack or pull of the ink is greater than the surface strength of the paper. pigment Substance, usually mineral or inorganic compounds, used to give paper its color. pigmented paper Also known as film coated paper. It is a result of a light film applied to the paper at the size press of the paper machine to enhance the uniformity, smoothness and printability of an otherwise uncoated sheet. piling In reference to printing, transfer of mineral pigment from paper to offset blankets: building-up of ink on rollers or on the printing surfaces of plates and blankets. PIMA Paper Industry Management Association. Members are manufacturing and technical executives of pulp and paper mills. pinfeed Device that controls flow of paper into a machine by engraving pins with marginal punching. pinhole perforations Machine perforation. pinholes Tiny holes or imperfections on the surface of the paper caused by the presence of foreign matter on the paper surface during manufacture. planographic Image and non-image areas are printed on the same plate. Image areas receive ink. Non-image areas repel ink. plastic binding Solid-back pronged comb is rolled back to make a cylinder. The prongs fit into slots punched along the binding edge of the paper to be bound. Combs are available in a variety of backbone dimensions. plastic laminated paper Some cover papers are laminated with plastic, all are extremely strong. plate finish A hard finished paper. plate paper Used in steel and copper plate engraving for proofing. plate wiping paper Used as a wiping cloth by engravers. platen Flatbed for the printing form and a flat plate to apply the pressure. plater Equipment consisting of cold iron rolls that imparts a high finish to paper. playing card stock A pasted card stock highly polished and lacquered. ply One layer or sheet of paper or paperboard that makes up a multi-layer aggregate. point In reference to paper, equal to one thousandth of an inch in the measure. Utilized when the thickness of paper is considered. points-per-pound Ratio obtained by dividing the result of a specific strength test by the basis weight of paper or board. Applied chiefly to tests for bursting strength. pole finish See loft dried papers. pop test The Mullen test which measures the bursting strength of paper. The expression evolved because paper makes a popping sound upon bursting when tested. porosity The degree of compactness of the fibers of the paper. For the explanation of the test to determine the porosity of the surface of paper or board, see Chapter 6. positive In reference to photography, the image on paper, film or glass that corresponds precisely to the original subject. positive plates Lithographic plates that can be directly posed in a camera from the original copy. Photographic negatives are eliminated. postcard Paper used for the production of postcards. This paper is available in uncoated stock, coated one side and cast- coated one side. poster board A heavy, stiff cardboard. poster paper (1) Paper that is designed for outdoor billboard advertising. (2) Term applied to a special mechanical pulp printing paper used for printed fliers and similar end uses. preconditioned paper Paper manufactured to specifications of relative humidity. presensitized plates Plates ready for exposure upon delivery from the manufacturer. press In reference to paper manufacture, the paper web passes through sets of rolls called the press. This occurs either to remove water from the web at the wet press; to smooth and level the sheet's surface at the smoothing press; or to apply surface treatments to the sheet at the size press. press proof Finished press sheets taken from the actual production run to check image, tone and color before final printing. pressboard Manufactured on a wet machine from sulphate pulp and cotton fiber or a combination of both and finished with a high polish. Thickness ranges from .031 to .250 of an inch. Principal qualities: uniform thickness and density, excellent ply adhesion and good forming and molding properties. Available in a variety of colors. pressmark In reference to paper manufacture, the design impressed into the web of paper by means of a rubber collar which carries the design. pressure-sensitive paper Paper that is coated on one or both sides with adhesive. This adhesive is activated by pressure. Usually used in the manufacture of labels and tapes. primary colors Yellow, red and blue. print-out Term for the product of any printer connected to a data processing system or operated off-line via tape from such a system. printability How well a particular sheet appears after the printing process in regards to ink receptivity, uniformity, smoothness, compressibility and opacity. It involves a complex interrelationship of many paper properties. Best methods for predicting printability are those which simulate actual printing conditions and which are reproducible from test to test. private brand See mill brand and merchant brand. process plates Two or more color plates in combination that produce other colors and shades. progressive proofs For process-color printing, engravers prepare a set of proofs showing each color separately and in combination proofed in proper color and rotated. These proofs are essential guides for the printer. proofread Reading and correcting proof early in production. proofs Samples of copy and layout produced at various stages of production. Following internal inspection, proofs are sent to the customer for approval. proprietary mill brand Paper retaining the name of the owner of the mill. (See mill brand). psychrometer Instrument that determines relative humidity. Wet and dry bulb temperature readings are compared with an RH chart. pucker During the drying process, a sheet that contracts unevenly will exhibit a bumpy-like effect on its surface. pulp Cellulose fiber material produced by chemical or mechanical means from which paper and paperboard is manufactured. Origins of this cellulose fiber are many. Among the sources are wood, cotton, flax, esparto grass, straw, jute, bagasse, bamboo, hemp, various leaf fibers and reeds. pulpboard Board usually made from pulp or wastepapers. pulping Process of transforming a cellulose raw material into pulp. pulpwood Wood, in the form of logs, or shorter lengths, that is suitable for the manufacture of wood pulp from which to make paper. puncture In reference to paper, resistance of paper or paperboard to perforation. pyroxylin coated board Paper coated with pyroxylin lacquer to make it water repellent and provide special properties of gloss. Gold, silver, copper and other metallic finishes are usual. pyroxylin paper A stock manufactured with a sulphite base which is lacquered for special pearly, bright, iridescent and metallic effects.
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