Caliper: The thickness of a substrate, usually expressed in thousandths of an inch (mils).
Cast Film: Plastic sheeting manufactured by the casting process, as opposed to the extruding process.
Central Impression: A press with a number of printing units around a large cylinder which serves as the impression cylinder against which the substrate rides.
Chemical Resistance: The resistance of a substrate to the deteriorating effects resulting from exposure to chemicals under specified conditions.
Coat Weight: Thickness / weight / amount of adhesive, ink, or topcoat.
Coating: In printing, an emulsion, varnish or lacquer applied in-line or off-line, often over a printed surface to give it added protection.
Co-Extrusions: Films produced by more than one extruder through a common die. Films have been made as many as thirteen layers.
Cold Key / Color Key: A series of colored films used to check individual colors and stripping. When overlaid in printing sequence, it will produce a multicolored image. Basically, it is a photographic positive of the separation negatives in generic color.
Cold Temperature Adhesive: An adhesive that will enable a pressure sensitive label to adhere or stick well when applied to a cold substrate, often in cold ambient temperature.
Color Matching: To duplicate the hue, value, and intensity of a given color sample usually by blending appropriate elements.
Color Process: A reproduction of any subject where the colors are separated by any method utilizing at least the three primary process colors; yellow, magenta, and cyan. Using halftone plates to produce intermediate colors and shades. Line work and screen work can be utilized.
Color Proof: A printed or simulated printed image of each process color (cyan, magenta, yellow and black) using inks, toners or dyes, to give a simulated impression of the final printed reproduction. Computers most often generate color proofs.
Color Separation: The process of separating colored originals into yellow, magenta, cyan and black printing negatives. Mostly done on computer controlled scanners.
Color Stations: Each printing section of the press or set of rollers used to print each individual color.
Color Transparency: A full-colored photographic positive image on a transparent support from which color separations are usually produced. Can be viewed with the aid of a lighted color transparency viewer.
Conformability: The ability of a pressure sensitive material to yield to the contours of a surface (curved, compound, or rough). See flexibility.
Converter: Refers to that type of manufacturer who produces plain or printed rolls, sheets, bags or pouches, etc., from rolls of film, foil or paper, including pressure sensitive.
Copy: Any furnished material (manuscript, pictures, artwork, etc.) to be used in the production of printing.
Core: The cylinder, upon which the label web is wound, typically made from kraft paper/glue or plastics.
Core Tag: Supplier identification or information label attached to the inside of the core.
Corner Radius: Describes the arc of curvature of the die blades where they meet so that they can impart a rounded corner to a die cut label or paperboard carton.
Cross Direction: The direction across the web. Papers are weaker and are affected more by changes in relative humidity in the cross direction than the grain direction.
Cure: To change the properties of adhesive, coatings or inks by chemical reaction. The “curing” of inks uses high intensity UV lamps whereas the “curing” or rubber requires considerable heat and pressure. Condensation, polymerization or vulcanization achieves “Curing.”
Cylinder: In flexography, most rollers in the printing press are called rolls with the exception of that upon which the rubber plates are mounted and the one which receives the impression and these are usually referred to as cylinders. I.e. plates cylinder, impression cylinder.