Tack - What is tack?
A property of materials that allows them to adhere to a surface immediately upon contact. Tack is sometimes referred to as the "stickiness“ of a material while it is in a fluid or semi-fluid state, and is a quality that allows immediate adhesion between two surfaces with a minimum of pressure and contact time.
In labelling, tack is an important factor in the production of adhesives, ink and toners, and various coatings that are used to produce pressure sensitive labels; these materials must be able to adhere to adjacent or subsequent layers to ensure that a label construction and its print remain together and in place on a substrate.
There are usually two stages of adhesion; instant adhesion and ultimate adhesion. In terms of tack, instant adhesion relies on an adhesive material having the property of good initial tack (it is sticky enough to adhere instantly to a surface) and ultimate adhesion involves the bond between the adhesive material and its adherend reaching the fullest strength possible, which involves the adhesive material setting into a hard film, at which point it will generally lose its tack.Go Back to Glossary