| C1S | | Coated One Side |
| C2S | | Coated Two Sides |
| Calender Rolls | | A set or stack of horizontal cast-iron rolls at the end of the paper machine. The paper is passed between the rolls to increase the smoothness and gloss of its surface. |
| Caliper | | See THICKNESS. |
| Carrier | | When referring to double-coated tapes, it is the thin medium to which the adhesive is anchored to on both sides. |
| Cast Coated | | Coated paper dried under pressure against a polished cylinder produce a high-gloss finish to the paper. |
| Chalking | | In printing, a term which refers to improper drying of ink. Pigment dusts off because the vehicle has been absorbed too rapidly into the paper. |
| Chemical Pulp | | In papermaking, treatment of wood chips with chemicals to remove impurities such as lignin, resins and gums and to separate the wood fibers. There are two types, sulfite and sulfate. |
| Chemical Resistance | | The resistance of a PS label to the deteriorating effects of exposure to various chemicals under specified conditions. |
| CK | | Calendered Kraft |
| Clear Coat | | A varnish. A coating that protects the printing and the surface of a pressure-sensitive label from abrasion, sunlight, chemicals, moisture, or a combination of these. |
| Coated Paper | | General term applying to all papers which have been surface coated with pigments. |
| Coater | | A machine composed of an unwind stand, coating devices, rollers, ovens and wind-up stand used to apply adhesive to backing and or carriers to produce a pressure-sensitive tape. |
| Coating | | A material, usually liquid, used to form a covering film over a surface. Its function is to decorate and or protect the surface from destructive agents or environment. |
| Coating Weight | | The amount or weight of coating (normally adhesive) per unit area. This can be expressed as grams per square meter or pounds per ream. |
| Cohesion | | The internal strength of an adhesive, its resistance to flow, and the resistance to failure or splitting when labels are removed, or under stress. |
| Cohesive Strength | | The internal strength of an adhesive and its ability to resist splitting caused by external forces. It is measured by its resistance to forces parallel to the surface. Good cohesion is necessary for clean removal. |
| Cold Flow | | The flow of a PS adhesive under pressure or stress. |
| Color Separation | | In photography, the process of separating color originals into the primary printing color components in negative or positive form. In lithographic platemaking, the manual separation of colors by handwork performed directly on the printing surface. An artist can pre-separate by using separate overlays for each color. |
| Conformability | | The ability of a PS material to yield to the contours of a curved or rough surface. |
| Contact Print | | A photographic print made from a negative or positive in contact with a sensitized paper, film, or printing plate. |
| Contact Screen | | A photographically-made halftone screen on film having a dot structure of graded density, used in vacuum contact with the photographic film to produce halftones. |
| Continuous Tone | | A photographic image which contains gradient tones from black to white |
| Contrast | | The tonal gradation between the highlights, middle tones, and shadows in an original or reproduction. |
| Core | | A honeycomb or variegated structure used in sandwich panel construction. The innermost portion of a multi-layer adherent surface. |
| Core Plugs | | Metal wood or compressed paper pulps which are driven into the paper core of the finished roll to prevent crushing or the damaging of the core. |
| Corrugated Board | | Kraft or jute board consisting of two sheets of flat board glued with one sheet of corrugated board between. |
| Coupon Base | | A splittable film product with adhesive and protective liner. When used in combination with another pressure-sensitive coated facestock affords the label converter the capability of manufacturing on press a redemption coupon that has a lift tab and is printed on both sides. A clear film remains on the labeled item after the coupon has been removed. |
| Crazing | | The network of small cracks that can appear in a varnish coat or plastic facestock. Usually caused by a combination of expansion and contraction during weathering or excessive solvents in an ink system. |
| Creep | | The small slow movement of the adhesive caused by continuing stress due to low cohesive strength. |