Mottling is the uneven appearance of print, particularly in solid areas: small dark and light areas appearing in the surface of paper (board).
Print mottle is influenced by many parameters, but the most important one is the type of paper. Variations in the surface characteristics such as absorption and smoothness play an important role.
At Smithers Pira, the IGT AIC2-5 printability tester is used to simulate press conditions which cause the mottle of specific ink and paper combinations.
Smithers Pira also employs a range of image analysis techniques to investigate print mottle, ink spread and print sharpness relative to inkjet and laser print. The PIAS®-II high-performance digital is used for objective image quality analysis.