What is sgraffito?
Sgraffito is a decorative technique for walls and facades in which two or more layers of plaster in contrasting colours are applied on top of each other and the top layer is partly scratched away while it is still fresh. Where it is removed, the colour underneath shows through, creating a design of lines and areas. The name comes from the Italian graffiare, to scratch.
How it works
- A levelling coat is applied to a sound, dampened background.
- One or more thin coats of lime plaster follow, each tinted with pigment, for example a dark lower coat and a light top coat.
- The design is transferred to the fresh top coat with a stencil or a pricked cartoon.
- Using scrapers, knives and loop tools, the top coat is cut back to the required layer. This has to happen before the lime has set, so work proceeds panel by panel against the clock.
As with a fresco, the pigment is bound into the lime, so well-made exterior sgraffito can last for centuries.
Where you see it
- Renaissance Italy: palace facades in Rome, Florence and elsewhere, many now weathered.
- Central Europe: from the 16th century in Germany, Austria and Bohemia, often covering whole facades, as at Litomyšl Castle in the Czech Republic.
- Art Nouveau Brussels (c. 1890-1915): the best-known example is the Cauchie House (1905) in Etterbeek, home and studio of decorator Paul Cauchie, with the largest surviving sgraffito facade in Belgium; another is the Ciamberlani house by Paul Hankar.
Application: care and restoration
- Water is the main enemy. Keep gutters, copings and cornices above the sgraffito in good order; almost all damage starts with penetrating or rising damp.
- No cement, no impermeable paint. Repair with a lime mortar matched in strength and colour. Cement mortar, plastic paints or water-repellent coatings trap moisture and cause the old plaster to spall.
- Clean gently. No pressure washing and no acids; start with water and a soft brush and let a conservator do trial areas.
- Do not hack off loose areas. Hollow patches can often be secured by grout injection; leave that to a specialist conservator.
- Listed building? Work on historic sgraffito usually needs consent from the heritage authority.
Related terms
- Fresco
- Plaster coat
- Lime kiln
- Plaster base
- Spalling
- Listed building
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