Calendered
Paper subjected to smoothing and polishing between stacks of highly polished steam rollers (calenders), which can form part of the dry end of the paper machine.
Caliper
Measurement of the thickness of paper, expressed in thousandths of an inch (points or mils). The calliper can also be expressed in pages per inch (ppi), pages per centimetre (ppc) or thousandths of a millimetre (microns). Calliper is also the name of the tool used to measure the thickness.
Cast coated
A method of drying coated paper by contact of the freshly coated surface with highly polished chromium plated heated surface. Cast coated papers have an extremely high gloss finish for top quality printing. The finish is obtained by the coating mix solidifying while in contact with the polished surface resulting in a similar polished surface to the paper.
Chain of Custody (Coca)
Chalking
A powdering effect left on the surface of the paper after improper drying of the ink or coating. This occurs when the pigment within the ink or coating does not bind successfully to the paper stock.
Chemical pulp
Pulp made by means of chemicals that dissolve the bonding agent, called lignin, within the wood to separate the fibres.
CMYK
The primary pigment colours used in 4 colour process printing and most desktop publishing programs. CMY are the subtractive primary colours and are used to reproduce full colour on the printed sheet. If these pigments are combined in equal amounts, black is supposed to be produced, but because of imperfections with the pigments, a muddy brown colour is produced. For that reason, black (represented by K) is added to give definition to colour reproduction and to create bolder text.
Chlorine bleaching
Chlorine free pulp
Coated paper
Coated stocks: A coated stock has a surface coating that has been applied to make the surface more receptive for the reproduction of text and images in order to achieve sharper detail and improved colour density. By adding a coated clay pigment, the objective of coating the stock is to improve the smoothness and reduce the absorbency. Coated paper finishes can be categorized as matte, dull, cast, gloss, and high gloss. The coating can be on both sides of the stock (coated two sides, "C2S") or on one side only (coated one side, "C1S"). Coatings added to ground wood papers give them a greater degree of permanency and the natural tendency for goundwood papers to yellow is reduced.
Coating
The mixture of clay materials that are applied to paper to improve the smoothness of the paper’s surface and improves ink holdout during the printing process. 2. In reference to printing, it is a varnish, lacquer, emulsion or other layers added to a printed product to provide protection.
Colour Bars
Colour bars are also referred to as colour control bars, colour control strips, or proofing bars. Colour bars are rows of different colored patches printed in the trim area of the press sheet. They are used by proofers and press operators to control the trapping, ink density, dot gain, and print contrast of the proof or the printed sheet.
Commodity Papers
Paper that is average in quality and produced on very large paper machines at high volumes. It is generally easy to obtain and the price is economical.
Cover paper
Also known as Card Stock - A stiff heavyweight paper used when durability is a concern. It is used on items such as postcards, covers, menus, posters, announcements, folders and business cards. Some cover stocks have matching text or bond paper available.Cropmake an image or layout smaller by trimming off one or more of the edges. Cropping is done to focus attention on the main subject of the image by eliminate unwanted details form the outer edges.
Curl
The tendency for paper to be distorted and not lay flat when it encounters large changes in heat and humidity. Curl occurs either as roll set or structural curl. Roll set curl, which occurs across the grain of the sheet, is created as the result of the paper being formed and wrapped around a roll core in a circular production process.
Cyan
A shade of greenish-blue also known as process blue. It is one of the subtractive primary colours (the others are magenta and yellow) which form the basis of colour printing. Cyan is complementary to, or opposite of, the additive primary red. This is because cyan is formed when the additive primaries other than red, (green and blue) are mixed together.