Transcription: The beams pass through the holes in a metal plate called a shadow mask. The purpose of the mask is to keep the electron beams precisely aligned with their targets on the inside of the CRT's screen. The CRT's dot pitch is the measurement of how close the holes are to each other. The closer the holes, the smaller the dot pitch. This in turn creates a sharper image. The holes in most shadow masks are arranged in triangles, with the important exception of those of the Trinitron CRT used by many monitor manufacturers. The Trinitron's holes are arranged as parallel slots.
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