Three key elements make up a label: face stock, release liner, and adhesive.
Face stock is the material of the label that carries the imprint. The print can be applied by several methods from desktop printers to industrial printing presses. Face stock materials are typically paper-coated or uncoated films that include polyester, polypropylene, vinyl, and Tyvek®. The type of face stock chosen depends on the intended use of the label.
A release liner is a film, paper, or coated paper material that is coated with silicone. The coated side of a release liner has pressure sensitive adhesive applied to it. The face stock is then laminated to the adhesive. The release liner protects the adhesive until the label is applied. The silicone coating ensures clean removal of the face stock and adhesive from the release liner.
A pressure sensitive adhesive is applied to a release liner and then affixed to a face stock. To stick the label to an item, the adhesive requires pressure either by hand or by application equipment.