Polished plaster is a term for the finish of some plasters and for the description of new and updated forms of traditional Italian plaster finishes.
The term covers a whole range of decorative plaster finishes - from the very highly polished Venetian plaster and Marmorino to the rugged look of textured polished plasters. Polished plaster itself tends to consist of slaked lime, marble dust, and/or marble chips (which give each plaster its distinctive look).
Polished plaster is mainly used internally, on walls and ceilings, to give a finish that looks like polished marble, travertine, or limestone.
Such plasters are usually applied over a primer and key-coat base, from 1 to 4 layers. They are finished (burnished) with a specialised steel trowel to a smooth glass-like sheen.
Polished plaster is usually sealed with a protective layer of wax.