History
The first schools to produce Scagliola inlay were found in Austria,
Germany and mainly Italy, at Carpi (hence the name "Scagliola
Carpigiana"). The level of skill achieved by scagliola artists
in Bavaria and Carpi starting from the late sixteenth and throughout
the seventeenth and eighteenth centuries is the highest testimony
to this form of art.
Scagliola is derived from Selenite (by-hydrated calcium
sulphite), a mineral commonly found in flakes form (scagliola
is Italian for flake). The selenite flakes used to be extracted
and placed in furnaces, where once reached a temperature of 128º
C they dehydrate and start to pulverise.
This powdered selenite would then be removed from the furnace
and fully ground to powder in mortars. Once impurities were sieved
to leave a white powder, Scagliola was finally obtained. When
mixed with water, the powder regains its original structure, but
the gesso obtained in this way is fragile and brittle. The gesso
is then mixed with glue, desiccated and treated with oils and
waxes, it acquires sufficient hardness with good strength properties
and impermeability.
The best schools of Scagliola artists were concentrated in the
Emilia Romagna Apennine region, particularly in the Carpi area
near Modena.
Work Stages
The main stages in the execution of Scagliola inlay
on marble are:
Stage1. After a design is drawn and the relevant tracing
transferred, cutting out starts
Stage 2. The hollowed elements in the design are filled with a
paste of coloured scagliola (made of selenite powder mixed with
pigments and natural glues) with a scraper or the paste in more
liquid state is poured according to the desired type of stone
imitation
Stage 3. Proud parts of the design are smoothed and sanded with
pumice stone.
Stage 4. Where the scagliola presents a porous appearance, this
is filled with appropriate colours
Stage 5. After sanding filled areas according to the design, the
cycle of cutting out, filling and smoothing may need to be repeated
The final stage consists of wax polishing or applying appropriate
protective transparent coatings.
