One of two major technologies use to manufacture cathode ray tube (CRT) televisions and computer displays. (The other is aperture grille.) Tiny holes in a metal plate separate the colored phosphors in the layer behind the front glass of the screen. All early televisions and the majority of computer monitors, past and present, use shadow mask technology.
While many long considered aperture grille technology to produce superior images, advances in shadow mask and hybrid technologies since the 1990s have made people's preferences more a matter of personal choice or specific application. The arrival of inexpensive liquid crystal display (LCD) monitors and other flat-screen designs now challenges both aperture grille and shadow mask CRTs' long reign as the technology behind the screens we look at.