Hand beaters must have enough mass to force the weaving into place, so they come in a variety of weights and sizes. Some may have lead inserts to provide additional heft for a smaller beater, and some are made entirely from metal.
Loom beaters typically take the form of a bar mounted across the loom. The actual beating is done by a metal insert known as a reed, which contains a number of slots, known as dents, which the warp threads pass through. This is the more common form, as floor looms and mechanized looms both use a beater with a reed.
Modern day beaters can have place for many different coloured threads that get thrown across the silk as the weaver pulls down on the loom.