Venetian plaster

Venetian plaster [ vəˌniːʃn ˈplɑːstə(r) ] [synonyms: polished plaster, Italian plaster, marble plaster] [Italian equivalent: Stucco Veneziano, Grassello di Calce, Marmorino, Stucco Lucido] is a special decorative plaster made of aged lime putty and marble dust, sometimes enhanced with acrylic resins, capable of creating a smooth, compact look with a high sheen or textured, stone or marble-like surface.

History of Venetian plaster

Venetian polished plaster evolved from Lime Plaster, which is used for decorative purposes since the end of the eighth millennium BC.

Lime plaster is composed of hydrated lime, sand and water but traditional lime plaster also contained horse hair to reinforce it.

It was used for building purposes in ancient Egypt, Malta and China and some of these architectural wonders can still be seen today.

Marcus Vitruvius Pullio, arguably the greatest Roman architect was the first to write about Venetian Plaster in his book De Architectura Libri Decem in the first century B.C. It originated as a technique to replicate the look of expensive materials such as marble or granite and to do so the Romans used a number of thick layers, sometimes as many as ten to create a smooth and enduring surface.

Naturally, with the modern decorative plasters of today, there is no need for more than three. Sometimes they added terracotta granulate to the plaster, which, because of its porosity could absorb a greater amount of the soluble salt contained in damp walls.

The idea of adding different materials to lime plaster to enhance some of it`s attributes started with Opus Signum or CoccioPesto, which is a actually tiles (sometimes pottery) broken up into very small pieces, mixed with mortar, and then beaten down with a rammer.

Opus Signum (fine roman concrete) is so solid that you can still see it at the Welwyn roman baths or at the the Wearmouth-Jarrow monastery. 

The seven step process of Marmoratum Opus (meaning marble capable of taking a high polish) was described by Vitruvius but it was Pliny the Elder in his Naturalis Historia (Books XXXIII–XXXVII) who expanded on Vitruvius' work and wrote of the Roman's method of slaking limestone, keeping it in covered pits and in dark cellars for three years.

The maturing of the limestone was a secret process and the final product was considered much like fine wine. The reason of the process was to prevent the carbonation which would reduce the causticity, binding, and hardening nature of the polished plaster.

Pliny the Elder (who also provided us with the most comprehensive information regarding the creation of mosaic art) was convinced that ancient stuccos were superior because of the length of time the lime putty was matured and because of the time dedicated to chopping and beating it.

Venetian plaster on Pallazzos in Venice

Modern Venetian Plaster

The art of Venetian plastering was reintroduced in the 16th century by the architect Palladio when they started to decorate the palazzos of Venice with Marmorino (meaning 'small marble') and Grassello di Calce (meaning 'fat lime').

Because of the light weight of polished plaster finishes, the pallazzos that are supported on columns and could sink into the mud could still be decorated with a prestigious marble-like finish. One type of plastering evolved from and is very similar to, but not to be confused with Venetian plastering is called Scagliola.

Scagliola is made of batches of pigmented plaster and glue (resin), capable of creating surfaces that resemble marble or semi-precious stones.  A great example of a column decorated with the scagliola method can still be seen in the Dropmore House, Buckinghamshire. 

Stucco Veneziano was nearly forgotten until a new Renaissance of Venetian plaster was fueled by the architect Carlo Scapa (June 2, 1906 – November 28, 1978). Scarpa was greatly influenced by the simplicity and elegance of Venetian and Japanese architecture and to combine useful and beautiful he used his Stucco Lucido or Intonachino marble plaster finishes extensively in his projects.

With the help of Eugenio De Luigi he experimented with adding animal hide glues and later acrylic resins to the plaster to enhance it's sheen. These semi-synthetic plasters had more intense colours,  were more cost effective and could be applied thinner over the surface.

Three of his most famous works are the interiors of Banca Popolare di Verona, Fondazione Querini Stampalia and the Olivetti shop in the Piazza San Marco in Venice, all of them have amazing feature walls with surfaces of Stucco Veneziano.

Modern Venetian plaster

Venetian plaster types and methods

Traditional polished plaster is hydraulic lime putty mixed with marble dust, coloured with natural pigments. Basically, limestone is transformed from raw stone into kiln-fired quicklime, then through slaking with water into a thick putty, but once it is applied, the plastered walls re-crystallize over time by absorbing carbon dioxide from the air; essentially it changes back into limestone, thereby creating an unparalleled enduring, crystalline beauty.

Acrylic Italian decorative plasters have synthetic additives which enable higher glossiness, enhanced hardness, flexibility and they usually dry slower. In the early 80's they were considered inferior to traditional plasters but after extensive R&D and tests, a new range with improved durability and look emerged. Nowadays there are many looks and applications which require synthetic Venetian plasters.

Venetian plasters can be categorized based on the added marble dust's grit size from Lucido (glossy) to Intona (exterior render, grit size 1.2mm<).

Venetian plasters are applied over a smooth surface by trowel or spatula in thin coats, allowing each new coat to add to the texture, depth and variation, creating a stunning final finish. The added marble powder makes it possible to burnish the surface, which is essentially a kind of wet-polishing of the final coat with a special, round-edged Venetian plastering trowel. The heat and pressure of the troweling creates deep, textured colours and very high shine. This final step makes Venetian plaster 'alive'.

Lime based Venetian plasters' advantages are that they have a very low VOC level (meaning harmful chemicals), because of their alkalinity they are hypoallergenic, mold and algae resistant and ​by absorbing and releasing water when they're unprotected (called 'breathing'), they regulate humidity. Lime based Italian plasters are suitable for restoration and listed buildings.

Venetian plasters can be combined with colour washes and metallic effects to achive bespoke, one-of-a-kind look. To see some amazing examples, please visit one of our showrooms!

Italian plaster exterior

Design and Projects with Venetian plaster

There are virtually thousands of design combinations available in any texture, sheen or colour; the finishes can be applied to flat or curved surfaces of almost any material used in the construction industry, even wood, metal, glass and paint. 

Our Venetian plasters are made from the finest raw materials with the highest environmental standards crafted for interior and exterior use with unmatched beauty, versatility and ease of use for the look you desire. If you would like to see some stunning projects featuring Venetian plasters, polished plasters and high-end Italian finishes, please visit our gallery!

Most of our finishes are eco-friendly ISO14001 certified, with LEED certificates and can be specified for exteriors, interiors, wet rooms or feature walls. For more information please call +44 (0) 208 458 1969!