Know Your Faux and Your Faux Finisher
Plasters
Plaster is often used in Faux Finishing to create textures for wall and furniture surfaces,
as in Venetian Plaster and also in stenciling for raised details. For these processes,
artists use limestone based plasters or new user friendly acrylic based plaster.
Venetian plaster is a smooth and often shiny plaster design that appears textured but is smooth to the touch.
Venetian plaster is one of the most popular and traditional plaster decorations.
Venetian plaster (or Stucco Veneziano) is a faux painting or faux finishing technique using thin
layers of plaster applied with a spatula or trowel and then burnished to create a smooth surface
with the illusion of depth and texture.
The Venetian Plaster finish known as Travertino is a totally natural lime-based product.
As it’s name suggests, it has a pitted appearance, like that of natural travertine stone.
Travertino
is a beautiful natural-looking finish. The unique way in which it is applied allows
for a two-colour combination which can work really well, perhaps with a darker or toning shade
showing through the pitted surface.
Lime plaster...is a mixture of calcium hydroxide and sand (or other inert fillers).
Carbon dioxide in the atmosphere causes the plaster to set by transforming the calcium hydroxide
into calcium carbonate (limestone). Whitewash is based on the same chemistry.
To make lime plaster, Limestone (calcium carbonate) is heated to produce quicklime (calcium oxide).
Water is then added to produce slaked lime (calcium hydroxide), which is sold as a white powder.
Additional water is added to form a paste prior to use. The paste may be stored in air-tight containers.
Once exposed to the atmosphere, the calcium hydroxide turns back into limestone, causing the plaster to set.
Lime plaster is used for true frescoes. Pigments, diluted in water, are applied to the still wet plaster.
Traditional stucco is made of lime, sand, and water. Modern stucco is made of Portland cement, sand, and water.
Marmorino...another polished plaster developed in the mid 15th century by Venetian Stuccatore to
emulate the effect of marble.
Produced, like the Stucco Veneziano, from the highest quality Italian slaked limestone, but this
time with an aggregate made up of larger marble particles.
It’s prominent use in Venice is due to it’s lightness of weight in comparison to the real stone,
marble, which caused architects at the time some concern, as their worst fear would be that the
island of Venice could sink into the mud flats, unable to carry the weight of it’s many palaces
and over 1,000 churches.
Sgraffito technique also known as graffito (scratched onto the wall graffiti, as we would know it)
was introduced by the Italians to Germany during the same period (16th C). Vasari described this
method for decorating building facades as a ‘quick and durable method’
a new highly decorative internal plaster was developed called Scagiola.
The composition was of gypsum plaster, animal glue and pigments.
It was used to imitate coloured marble, though of course, in a much lighter form,
it being a very fine surface coating. Sand, marble dust and lime were sometimes added.
The 17th century saw a golden era for Scagiola plasterers, who were mostly Italian monks.
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