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Painted Plaster from the Roman Villa

Bradford on Avon, Wiltshire

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painted plaster, Roman Villa bath house

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When the baths of the Bradford on Avon Roman Villa were excavated in 1976, hundreds of pieces of painted plaster were found. They would have fallen from the walls as they became ruined and were robbed of their stone for later buildings.

The walls had been plastered with a coarse mix of ground limestone and red brick in lime, 30 to 40mm thick. A thin finishing coat of almost pure lime would have been skimmed over the top. The painted decoration would have been added while the plaster was still fresh (fresco in Italian) so that the colour became bound into the lime as it slowly set.

painted plaster

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The colours were mainly derived from minerals. Red was a favourite and would have been of red ochre, made from ground haematite, an oxide of iron. Contrasting greens came from the copper carbonate mineral malachite. Blue was more difficult to find in nature. Lapis lazuli came from distant Central Asia and would have been extremely expensive. Substitutes may have been azurite, another copper mineral, or finely ground cobalt blue glass. Chalk gives white and cream shades when mixed with yellow ochre (the iron oxide mineral limonite). Black would be carbon.