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Reflectivity |
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Ability of paper or paperboard to reflect light from its surface. It is a measure of gloss. |
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Register |
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Placement of two or more images on a sheet of paper to align them with each other. |
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Register Paper |
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A type of paper made for easy removal from sticky surfaces. |
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Reinforcement |
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Reinforcement Pulp |
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Softwood chemical pulp added for giving paper a greater strength. The reinforcement also improves runnability of paper on the paper machine and printing presses. |
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Rejects |
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Material removed and discarded during the cleaning or screening of pulp and papermaking stock. |
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Relative Density |
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Mass of per unit volume of a substance. |
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Relative Humidity |
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The percentage of moisture in the air relative to the moisture it can hold without saturation. |
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Release Paper |
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Backing paper for self-adhesives. Release paper is used to prevent the sticking of glue to other surfaces. |
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Renewable Resource |
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A naturally occurring raw material or form of energy with the capacity to replenish itself through the ecological cycles. |
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Reproduction Paper |
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A one-side coated paper suitable for fine screen and color printing. |
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Residues |
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Useful material left over or arising during production or use and which is recovered. |
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Retention |
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Percentage of the amount of filler in the finished paper web relative to what was added into the furnish |
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Rewinder |
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An equipment used to slit a large width roll into a smaller width rolls of various sizes to meet specific customer orders. |
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Ribs |
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Thin bars of wood, which support the wire cover of a mould. |
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Rice Paper |
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A misnomer used to describe Oriental papers. The name might have been derived from the rice size once used in Japanese papermaking. |
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Right Side of Paper |
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The side on which the watermark is read correctly. |
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Ring Crush Test |
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A test, which measures the stiffness of paper. |
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Roll Coating |
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A process in which the coating is applied by a roll. A reverse roll contacting the freshly coated surface subsequently smoothens the coating. |
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Roofing Paper |
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A type of paperboard impregnated with tar, bitumen, and/ or natural asphalt. |
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Rosin |
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A byproduct of turpentine distillation from the gum of resinous woods. It is used for internal sizing for paper to make it water resistant. |
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Rosin Size |
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A soap solution of rosin and caustic soda. It is added to paper or paperboard to make them water resistant. |
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Rotary Cutter |
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The machine that converts paper rolls into untrimmed sheets. |
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Rotogravure Paper |
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A highly smooth and uncoated groundwood paper used in rotogravure printing of magazines and catalogues. |
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Rotogravure Printing |
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A printing process where the images are engraved in the form of cells on the surface of a metal cylinder. |
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Rough Paper |
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A textured paper surface obtained by placing the wet paper sheets against textured blankets. |
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Rough Shake |
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A sheet of paper in which the fibers are randomly distributed, as in handmade papers. |
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Round Cornering |
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Rounding of corners of paper forms and books by a machine. |
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Rub Proof |
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A state of printed ink under the maximum dryness. In this state the ink does not smudge. |
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Runnability |
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A paper property necessary for a trouble-free run through a paper machine or printing press. |
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Running Head |
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A title at the top of a page that appears on all pages or chapter of a book. |