Wednesday, 30 September 2009

History of Marmorino (Venetian Plaster)

Venetian plaster is different than other plastering techniques. It is multi-layered with a highly polished smooth surface which can be tinted with pigment, not covered with images or bright colours.
Even today it is a unique finish and this is mainly due to the processes and ingredients that have changed little since the first century AD.
The popularity of Venetian Plastering today is a result of its rediscovery in the Italian Renaissance. As a result of architects and artists embracing Venetian plaster it became a highly sought after finish for interior and exterior walls.
Essentially the base of Venetian Plaster has stayed the same - limestone, with a stone or marble powder for later layers.
In the fourth century BC Romans discovered that limestone, when mixed with volcanic material such as silica or alumina, would set and harden under all kinds of conditions, even under water. They also kept limestone in pits and dark cellars for three years to allow it to mature, and realised that when the limestone plaster was exposed to the atmosphere it could absorb atmospheric gases. This neutralised it, making it easier to use.
In the fifteenth century a lighter finish that resembled marble was developed – Marmorino. It was popularly used on the surfaces of buildings in Venice where it was necessary to keep them as light as possible. Many of the buildings had weak foundations and therefore were unsuitable for using marble slabs. The alternative, Marmorino, provided a smooth reflective surface that allowed the building to breathe in the moist Venetian lagoon environment.
Our modern version of Venetian Plaster is mainly due to an Italian architect called Carlo Scarpa. Many believe without him the skills of Venetian Plaster would have died away by now. In the mid 1900s he began using glues and acrylic resins. Along with other artisans he was responsible for reducing the layers required from seven to three.

The rich tradition of Venetian Plaster can now be found in Stucco Italiano’s MARMORINO VENEZIANO products which have adapted to the necessities of present-day application and colouring needs.

Friday, 18 September 2009

What differences could there be in products that claim to be ‘Marmorino’, ‘Marmorino Veneziano’, ‘Polished Plaster’ and ‘Italian Stucco’?

While many companies may brand their product under a term such as Marmorino or Venetian Polished Plaster the products can differ in terms of texture, appearance, ingredients and cost.

Venetian Plaster normally refers to a smooth shiny polished surface, however depending on the manufacturer it could refer to a wide range of plaster products, not just from Italy. Many manufacturers use the term to add value to their cheaper products.
Marmorino, while refers to a smooth, shiny polished plaster can further be categorised depending on it texture, grain size or shine. For example Stucco Italiano provides Classic Marmorino which has the smallest grain size and therefore provides the smoothest surface with the highest shine. Stucco Italiano's Carrara Marmorino has a slightly coarser grain size giving a slightly rougher texture with a more matt shine. There is also a coarser grain Carrara Marmorino available from Stucco Italiano as a special request for the more experienced artisan. Stucco Italiano also provides Marmorino flooringwhich is a stronger version which has a more matt shine; however unlike the others which are all lime based Stucco Italiano flooring Marmorino has cement content.

Some Marmorino or Polished plaster products may be made from Lime-based ingredients, others could be cement based or acrylic.
Lime-based Polished Plasters
Generally lime based polished plaster is supplied as a pre-mixed wet material and contains a minimum of 40% marble powders with no more than 2% binders. This is recognised within restoration projects as a suitable quality material. The end result should be smooth and cold to the touch without reliance on wax or machines to make it shiny. Waxing is an option but if this product is installed by a talented craftsperson there should be adequate shine in the polished plaster with waxing only being used for protection.

Cement based polished plasters
Polished plasters with cement content are supplied as a dry mix, thus making them less shiny and cheaper than lime-based polished plasters. Normally wax is needed to achieve a high shine. The disadvantage of the high shine due to waxing means the shine will dull over a period of time and result in it having to be rewaxed to maintain the high shine.

Acrylic Polished Plasters
The appearance of acrylic polished plasters tends not to be as rich as the original lime-based polished plasters. They would not be cold to the touch.

An important point to remember is you should always request a sample and technical information to ensure you know which Polished Plaster you are getting.

Thursday, 17 September 2009

What is ‘Marmorino’, ‘Marmorino Veneziano’, ‘Polished Plaster’ and ‘Itallian Stucco’? Do they mean the same thing?

Many people refer to the same type of product when they use terms such as Marmorino, Venetian Plaster, Polished Plaster, Stucco, Lucidato, Spatulata, Veneziano plus others. Generally these terms can mean the same style of product, however it is worth noting it could also mean something different (such as difference in texture or appearance) depending on how companies brand their product.

Throughout this blog I will refer to the range of products as Marmorino or Polished Plaster which are most often used in the UK and Ireland.

Understanding Polished Plaster/Marmorino and Venetian Polished Plaster

Over the coming weeks I will be discussing a range of topics in the hope they may answer some of the questions you may have about the product and give you an understanding of the history to help you appreciate the skill gained by the artisans of these decortaive finishes.