ISO 8296:2003 specifies a method for determining the wetting tension of surfaces of plastic film and sheeting in contact with drops of specific test solutions.
The ability of plastic films to retain inks, coatings, adhesives, etc., is primarily dependent on the character of their surfaces, and can be improved by one of several surface-treatment techniques. These same treatment techniques have been found to increase the wetting tension of a plastic film surface in contact with mixtures of solvents. It is therefore possible to relate the wetting tension of a plastic film surface to its ability to accept and retain inks, coatings, adhesives, etc. The measured wetting tension of a specific film surface can only be related to acceptable ink, coating, or adhesive retention through experience. Wetting tension, in itself, is not a completely acceptable measure of ink, coating or adhesive adhesion.
The test is not applicable when the surface of the material to be tested reacts chemically with the test solution.