Polished plaster is a term for the finish of some plaster 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 basecoat base, from 1 to 4 layers. They are finished (burnished) with a specialised steel trowel to produce the desired amount of sheen. Polished plaster is usually sealed with a protective layer of wax.
Modern polished plaster is a generic term for various styles of these finishes, encompassing additives and resins that make the material more durable.
Decorative plaster was first found in the Mesopotamia region in 9000 B.C. It was later discovered in Egyptian tombs as part of ancient burial artwork. Polished plaster became quite common in Europe during the Middle Ages, when animal hair, beer, eggs, and malt were added to the mortar to improve its strength.
Venetian plaster is the oldest known building material used to create decorative wall surfaces. Venetian plaster is also known as Italian plaster or Stucco veneziano. Venetian plaster is a wall and ceiling finish consisting of plaster mixed with marble dust, applied with a spatula or trowel in thin, multiple layers, which are then burnished to create a smooth surface represents a classic interior finish.
Tadelakt is a nearly waterproof lime plaster which can be used on the interior and exteriors of buildings. It is the traditional coating of the palaces, hammams and bathrooms of the riads in Morocco. Tadelakt has a luxurious, soft aspect with undulations due to the work of the artisans who finish it.
Marmorino is a special type of wall covering. It differs from other types of plaster in that it consists of powdered marble mixed and a paste of lime.
Marmorino dates back to ancient Rome, but only became popularly known as marmorino veneziano after it was rediscovered in the 15th century and became popular in and around the city of Venice. Its use spread as it became a mark of wealth, opulence, and fine craftsmanship. This can then be applied to make many deferent textures, from polished marble to natural stone effects. Widely used in Italy, it now become known worldwide.,
As a wall covering, marmorino is very durable. When dried and cured, it nearly approaches limestone in strength, allowing thin layers to last many centuries. It is water resistant, and so is suitable for exterior walls. It is permeable to both air and moisture, allowing moisture to escape and evaporate quickly, preventing mold growth inside walls, and the chemical make-up of the marmorino itself is also a retardant to mold.
Some of the most popular Marmorino finishes types are: Pitted lime stone, travertine stone and dragged stone finish.