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Shown below are the definitions for: T
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tab forms Continuous forms.
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tablet papers A grade of paper (usually 16 pound on a 17" x 22"-500 basis) used for the manufacture of writing tablets.
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tack Refers to the internal "stickiness" (cohesion) of an ink; a measurement of the resistance to splitting of an ink film between two separating surfaces; tack is necessary in lithographic inks to insure adequate film splitting at the thin ink film thickness' necessary for this planographic process. High tack does stress the paper surface as the ink film is split from the blanket to the paper surface. If that film splitting stress is sufficient, the paper surface can be disrupted, with pick resulting. Tack is an ink characteristic that can be measured by instrumentation (such as with an inkometer); other ink fluid characteristics are described by "viscosity" and "length".
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tail end hook/curl Downward curl at the delivery end of a sheet fed offset press, and is a distortion created by the inked paper clinging to the blanket and the stresses of pulling the pa per away from the press blanket. It is noticeable only at the trailing edge of the sheet.
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TAPPI Abbreviation for "Technical Association of the Pulp and Paper Industry"; TAPPI standard conditions (see conditioning) refer to standard conditions of temperature and humidity for most paper tests.
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tear test Also tear strength; a test which determines the tearing resistance of paper; Elmendorf was an original manufacturer of the test equipment, and thus became a generic name for the test.
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telescoped roll Progressive roll edge misalignment, concave on one side, and convex on the other; also called "dished" roll for the concave side.
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tensile Strength property, measured as the force required to "pull" a paper sheet of specified dimensions, to failure; can also be expressed as "breaking length"-usually meters of length required for a web to be hung and break as a result of its own weight (gravity).
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text paper See "book papers".
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themography Also known as "raised printing" or by the trade named unit "Virkotype"; this process is used in conjunction with a printing unit (letterpress or offset lithography) with slow drying inks. Immediately after printing. the paper is dusted with a powdered compound and the excess which does not adhere to the wet ink film is removed. The ink and powder are then fused and swollen above the level of the paper, by elevated temperature/ heaters. This imparts an embossed or engraved appearance and feel.
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thermomechanical pulp Also "TMP"; a pulping process, that involves the hot, pressurized refining of wood chips; using an elevated temperature to assist the mechanical pulping process.
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thickness See "caliper".
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thixotropic The property of some inks and coatings of becoming more fluid (lower viscosity) when worked or stirred, and of setting to a less viscous or semi-solid state when at rest; see "dilatant".
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three-color process The printing of a full color picture or drawing by the use of only three separate colors: yellow, magenta, and cyan. These are also known as process yellow, process red, and process blue. Also see "four-color process".
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throw length In the forms printing business, line holes to guide a form on automated equipment, must line-up over a specified length of the continuous form, and from side to side. After printing, both side to side (mechanical condition of the roll-hard and soft edges), and from roll to roll for multi-part forms, alignment of holes is essential for proper subsequent handling and feeding.
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tight edges Also known as shrunken edges; these are the result of the sheet having lost moisture at the edges and shrunken to a smaller size. For this to happen, the sheets must be in a pile which prevents loss of moisture in the center of the sheet, which thus remains the same size. The sheets will usually be dished, with the corners raised. This is caused by a low relative humidity of the air to which the paper is exposed.
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titanium dioxide Also written in the chemical symbols Ti02; a mineral pigment which can be used in the furnish on a paper machine or in paper coatings; is of small particle size and imparts the greatest opacifying and brightening properties of the pigments used in producing and coating paper.
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tonal value Gradations of image density. Created: 1) In printing with a single color of ink, by separating the different tonal value areas into dots of varying size. This can create a full range of from less than 5% to 100% ink coverage of the paper area to be printed, depending upon the size of the dots of ink. Also, see "halftone". 2) In photography, on a continuous basis, based upon the chemistry and optics of the photographic process.
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toner The "ink" of electrostatic copying/printing, defining the image area; usually consists of a magnetic ingredient to be attracted to the charged area on the photoreceptor, a colorant material (black or other), and possibly an adhesive that can be melted (or "fused") to hold the composite "ink" on the surface of the paper being printed or receiving the copy.
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toning See "scumming".
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tooth A term which implies a rough finish to the surface of a sheet of paper.
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tracking The carrying of wet ink from the printed paper, through the printing press. and depositing at least a portion of the ink on parts in the press, with some then being re- deposited (tracked) on subsequent paper being processed.
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translucent The property of transmitting light, without being transparent.
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transparent ink See "process inks".
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trapping The term used to describe the acceptance of transfer of an ink by the surface being printed. Wet trapping refers to the acceptance of an ink film by a previously printed wet ink surface; dry trapping is of course the acceptance by the dry paper or printed ink film surface; see .1 color sequence" and "tack".
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trim marks In printing, marks placed on the copy to indicate the edge of the page or sheet, and where to "cut" or trim.
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trim 1) Indicates the maximum width of finished paper which can be made on a particular machine. 2) To remove from the edges of a sheet or roll, excess or unneeded paper. 3) The excess of paper allowed around a printed piece for bleed and/or handling and later trimming.
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trimmed size The final size of a printed piece after all bleeds and folds have been cut off.
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tub size See surface sizing; in the days of paper making by hand, the sheet of paper was surface sized by dipping the sheet in a "tub" or vat of starch or glue solution.
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tucker blade See "jaw fold(er)
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tunnel dryer Also "air dryer"; a well-insulated tunnel or large box through which paper is passed for the purpose of drying the paper, coating on the paper, or printing on the paper
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turn-up The completion of a roll of paper from a paper machine or coater, and the starting of a new roll.
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turning bars Metal bars or rollers at a 45-degree angle from the running direction of the web handling equipment (printing press, coater, etc.). Used to turn the web at right angles when feeding from the side or when used in multiples, to actually turn the web over. Often the bars are filled with air and perforated to reduce friction of the web travel. Also called "angle bars".
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turnover A slight tear in the edge of a web or sheet which is folded over during manufacture, converting, or printing; in a pile of paper is often called a "dog ear" from its appearance, when sticking out of the pile.
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twin wire A Fourdrinier paper making machine with two wires (not necessarily twins of each other in size or length) instead of one, to dewater the furnish and produce a sheet with less two sidedness
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two-sidedness In paper, the property denoting differences in appearance, properties, and possibly printability between the top (felt) and bottom (wire) sides.
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type face A design of letters of the alphabet intended to be used in combination.
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