A type of shadow mask used in CRTs. There are two methods. The first is the aperture grille used in Sony's Trinitron monitors, which uses vertical phosphor stripes and vertical slots in the mask compared to the traditional shadow mask that uses phosphor dots and round holes in the mask. The second is a combination of traditional shadow mask and aperture grille technologies used in NECT's CromaClear monitors. Sometimes known as a slotted shadow mask, this mask uses elliptical holes and vertical phosphor stripes.