In screen printing, a coating added to a film or to the screen fabric to eliminate blurring caused by light reflected from the base of the film or the fibers in the screen. Screen fabrics dyed yellow, orange, or red will cause halation.
In photography, antihalation refers to the elimination of a blurring effect caused by the reflection of light rays back through an exposed photographic emulsion. Antihalation of photographic films is usually effected by means of antihalation dye.