R
REAM
A term denoting a number of sheets of paper ranging from 480 to 516, most commonly 500.
REEL UP
The final process in paper making. After passing through the drying cylinders and, if appropriate, the calender rollers, the newly made paper is wound onto a jumbo reel. This is the reel up stage.
REFINER
A machine which is generally equipped with discs or with a cone and plug, intended for the treatment of fibrous materials in an aqueous medium to give them some of the properties needed for the manufacture of pulp or paper with the necessary characteristics.
REGISTER MARKS
The printed marks used to align color separations for printing so that each color registers with each other.
REINFORCED PAPER
Any paper that has been strengthened mechanically by the incorporation of other materials such as plastics, threads, cloth or strips of metal.
RELATIVE HUMIDITY
Relative Humidity is the moisture content in paper which should be the same as in the printing environment.
RETREE PAPER
Paper which has become available due to overmaking, side-runs or because it is in some way less than perfect. Although sold without a guarantee the substance and size tolerances would be expected to conform to industry standards. Often referred to as clearance paper.
RICE PAPER
A material that has the same appearance and purposes as paper, rice paper is not really paper, but the sliced and flattened pith of a plant that grows in Taiwan. It is very thin edible paper made from rice flour and water, used by Chinese artists as a surface for painting.
ROLL COATING
Any procedure of coating a web of paper in which the coating is applied directly to the paper by transfer from an applicator roll that carries the coating slip upon its surface. The applicator roll may rotate in the same direction as the paper web or in the reverse direction (reverse roll coating).
