Formerly the principal raw material used in the making process; often meaning cotton rags. Rag content describes the amount of cotton fibre relative to the total amount of material used in the pulp. "Rag content" is not widely used (or is a misnomer) today as more and more high quality paper is made not from rag but from linters.
Rag Content
The amount of rag fibres in a sheet, varying from 25% to 100%.
RAM
Random Access Memory
Raster Links
Evenly spaced striations that resemble a corduroy appearance.
Ream
A unit of measurement for sheets of paper; normally 500.
Reclaiming
The process of removing ink and stencil from a screen to enable that screen to be reused.
Recovered Fibre
A general term for fibre that has been collected for recycling, rather than being sent to landfill. Can include both pre- and post-consumer waste.
Recycled
Paper consisting of some amount of recovered or recycled cellulose fibres.
Recycling
The recycling of used product made from paper and cardboard (packaging, newspapers, etc.) is the return of these products into the production cycle of paper-cardboard. In the production process, the raw material is regenerated and converted in similar products. For example, a used cardboard box is turned into a new cardboard box, or old newspapers are reused for producing new newspapers.
Reel
A continuous length of paper wound on a core.
Registration
The colour to colour relationship in a printed image. The quality of the printed image depends on the accuracy of the registration.
Resin
A solid (or semi-solid) which can be dissolved to a liquid state, suspended in a vehicle to make an ink or coating and which, upon drying, forms the solid part of printed film.
Resolution
The sharpness and clarity of an image.
Retarder
An additive used in screen printing to slow the rate of drying in an ink.
RGB
Red Green Blue. Primary colours of light - used for all photographic and digital capture of coloured imaged by camera and scanners.
RIP
Raster Image Processor
RoHS
Restriction of Use of Certain Hazardous Substances in electrical and electronic equipment. Legislation that restricts the use of heavy metals and flame-retardants in some products and substrates. Related to WEEE. See: www.defra.gov.uk/environment
Roll size
The width of a roll of paper.
ROM
Read Only Memory
Runnability
Paper properties that affect the ability of the paper to run on the printing press.
