D.T. cover "Double-thick" describes a sheet of paper made by bonding two thicknesses of paper together resulting in an extra-stiff sheet. More common weights are 100 lb. (two 20 26-50 lb. sheets) and 130 lb. (two 20 26-65 lb. sheets). damask paper Writing paper with a finish resembling linen. damp streaks Streaks caused by uneven pressing or drying. dampeners In lithography, cloth covered, parchment paper or rubber rollers that distribute the dampening to the press plate. damping rolls Chilled cylinders, situated ahead of the calender stacks, condensing a continuous spray of steam and transferring the moisture to the web of paper as it passes to the calenders. Also a spray of moist steam or water on the web of paper. dancer rolls Sometimes called rider roller. Weighted roller that rides on the web between the roll of paper and the meeting unit to take up slack and keep the web at uniform tension. The Dancer Roll is interlocked with a brake on the roll to control unwinding. dandy roll (1) A plain roll situated above the wet web of the paper to provide a smoothing action to the top surface of the paper as it passes under the roll. (2) A watermarking dandy roll is a roll of skeletal structure, sheathed in a wire cloth that has designs, letters or figures affixed to it. As the wet paper web passes under the turning watermarking dandy the designs are impressed into the paper and a permanent watermark is left in the sheet (See watermark). de-inked paper stock Essentially, recycled paper. Ink has been removed by mechanical and chemical means to produce clean fibers. decalcomania paper A transfer paper designed to permit transfer of printed surface to objects such as china, glass, etc. Also referred to as a decal. deciduous Tree species that annually sheds its leaves. Wood from these trees are considered to be hardwoods such as maple, chestnut, birch, gum and poplar. deckle On the wet end of the paper machine the straps or deckle rulers that prevent the fiber from overflowing the sides of the machine. The deckle determines how wide the paper on a particular machine will be. deckle edge Refers to the feathered edge on paper produced when fibers flow against the deckle or edge of the web. Deliberately produced for aesthetic purposes, a deckle edge is found especially on formal stationery and announcements. A deckle edge can be created by an air jet, or also by a stream of water. deckle stain Paper that has a coloring or tint along the deckle edge. decorative papers Papers manufactured with embossed or printed designs of some type which are used primarily for decoration such as gift wrapping paper. These papers come in a variety of weights, grades, coatings, finishes and colors. deep etch plate Offset plate on which the image area is etched with a mordant etch a fraction of one one thousandth of an inch-0.0003-below the non-image area. The etched image is then built-up with an ink receptive base and inked as a planographic plate. defects Irregularities appearing on finished paper that spoil the appearance or cause weaknesses in the sheet. delamination Parting of layers of a sheet of paper made on a cylinder machine. deliveries In printing, presses deliver flat sheets, folded sheets, finished products (self-cover printed matter), or rewound rolls. delivery Area of the originating press where the freshly printed sheets are piled as they leave the impression section. densimeter Equipment used to analyze the porosity of a given sheet of paper. densitometer Reflection instrument measuring the density of colored ink to determine its consistency throughout a press run. density Identifies the weight of the paper compared to the volume. Density is directly related to the paper's absorbency, stiffness, opacity and resiliency. Dense papers are made from strongly beaten or hydrated pulp. desensitize Coating surface of a carbonless paper with desensitizing ink to inhibit image transfer. detail paper Thin, good quality hard-sized paper that is semi-translucent. diazo Copying process requiring a translucent master. It is reproduced by exposing a diazonium coated copy sheet to ultra- violet light through the original. die cutting Male and female dies are used to cut out paper or board in desired shapes. die wiping paper Paper designed to clean surface of printing plates in the intaglio process. dielectric papers Papers free of any metallic elements that might conduct electricity. dielectric strength The degree to which paper resists penetration of an electric charge. digester Pressure vessel in which wood chips are cooked to separate fibers from each other and to remove detrimental particles. dimensional stability Characteristic of paper to retain its dimensions in all directions under the stress of production and adverse changes in humidity. Laboratories at the paper mills measure the dimensional stability--expansion and shrinkage-- of paper on the following machines: Neenah Multiple Specimen Paper Expansimeter, TMI Expansion and Shrinkage Tester and the Patra Paper Expansion Measuring Device. dioxin The term often used to refer to TCDD and/or any of the family of chemicals composed of 75 dioxin congeners and 135 furan congeners. TCDD is the abbreviation for 2,3,7,8 tetrachlorodibenzo-p-dioxin. diploma parchment Paper made from cotton fibers to resemble animal parchment. Surface sized with high quality animal glue. Principal properties: durability and permanence. Basic size: 17" x 22". Substance weight: 48, 56, 72 and 88 lbs. direct halftone Halftone for which the screen negative was made directly from the subject to be reproduced. direct image master Duplicating master typed or drawn upon directly. direct process paper Fine paper designed to accept a light- sensitive coating. Copy paper for diazo reproduction. dirt Dirt in paper consists of any imbedded foreign matter or specks which contrast in color to the remainder of the sheet. An instrument, The Papric Counter, is used in laboratories to identify dirt specks measuring 0.04 square millimeters and larger. dished Concave rather than flat pile of paper. Also refers to roll ends of paper that are not flat. display board Pasted or unpasted boards used for advertising displays. distortion Forced out of shape. distributor Company which purchases paper from mill for resale to printers and end-users. Usually a distributor has protected or franchised product lines and territories. Inventory, warehousing, distribution and transportation of product are among the services offered to paper buyers. Also called merchant. doctor-blade Mechanism used during manufacture to clean the surface of the paper while on the paper machine roll. Running the width of the roll, the doctor blade scrapes excess pulp and size off the paper. Also, in gravure printing, a knife edged blade pressed against the engraved printing cylinder to wipe away the excess ink in the non-printing areas of the plate. dot Individual element of a halftone printing plate. dot gain When the dots in halftone printing become larger than desired. double calendered A paper run through two calenders. double cap Trade term for size 17" x 28" available in business papers. double coated A sheet that has been coated twice on the same side. Sometimes confused with a sheet coated on both sides. double deckle Papers having a deckle edge on two parallel edges of the sheet. Used only with machine-made papers. double imprint unit Two sets of printing cylinders that permit imprint to be altered as press continues to run at full speed. double printing Printing different negatives--line and halftone--in succession and in register on the same sheet of sensitized metal. double sizing The process of applying size a second time after first sizing has been dried. downtime When a normally operating paper machine is stopped for repairs it is said to be "down" or the mill is said to be in "downtime." Downtime can occur due to mechanical failure, change of grades in production and many other reasons. drawing paper Good quality, dull finished paper sufficiently stable to take erasures. drop out In printing, halftone with no screen dots in the highlights or background. Also, color not sensed by optical reading devices. Also, ink colors which will not image a photographic plate. dropped stub Stub tearline perforations on a business form that is lower than the stub width. A portion of the form is removed with the stub. drum coating Carbon application that transfers to the carbonizing base stock a pre-measured amount of coating from a rubber roller. drumhead manila Strong rope papers. Basic size: 24" x 36"/500 sheets. Basis weight: 140 lbs. dry finish Term indicating that paper or paperboard is calendered without use of water. Also paper with unglazed, rough finish obtained by the dry finish process. dry offset Letterset printing. dry-end The section on the machine where the driers, cutters, slitters and reels are located. dryer (drying oven) In printing, oven on web offset press through which the web of printed paper passes after it leaves the final printing unit. The drying process, standard when heat-set inks are used, heats the web to about 350 degrees Farenheit. Either gas or electricity dries the vehicles and air blasts drive off the volatile gases. dryers In papermaking, a series of large cylindrical steam heated rolls that dry the paper webs. The "dry-end" of the paper machine. dual distributor, dual house, dual merchant A paper distribution firm which deals in both fine and industrial papers. dual roll or stand Stand supporting two rolls, one above the other, to feed two webs of paper at the same time or to reduce reloading time when only one is used. dull coated Same as dull finish. Paper is said to be dull coated when it registers a gloss test reading less than 55%. Characteristically, dull coated or finished paper has a smooth surface and is low in gloss. dummy Page or set of pages assembled in the exact position, form and style desired for the finished piece of printed work. Used as a model or sample for the printer. duotone Two-color halftone reproduction from a black-and- white original. duplex Paper having a different color on each side. duplex coated bristol Used for advertising, postcards and folders, this paper is characterized by a solid center coated with a bright or deep color on one side and a harmonizing shade or white on the reverse. The center base is generally manufactured from softwood and hardwood chemical pulps, and is approximately 10 points in thickness and 22 1/2" x 28 1/2" in dimension. duplex coating Coating both sides of a sheet at the same time. dycril plate Photopolymer plate, which when developed and washed is a relief plate which is used for direct printing or letterset. dye transfer Copying process, the negative of which can be used again. dye-impressed master Hecto masters crash imprinted to reproduce in the duplicator. dylux A stable print specially sensitized on two-sided papers for proofing.
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