New data on 2000 year old plasters from Pompeii

The Basilica in Pompeii. Photo: Agneta Freccero

(Published 2013-02-28)
One of the newest additions to SND collections are data from 2000 year old plasters used for wall decorations in Pompeii. In the study Pompeian Plasters, Agneta Freccero, researcher in Conservation, analyzes the composition and chronology of the materials. One of her findings shows that the inhabitants of Pompeii were very aware of quality aspects and that the craftsmen made considerably greater efforts in public buildings than in simple households.

The big quality differences in Pompeii are not unlike the ones found in today's society. Agneta Freccero’s findings show that residents of the city sometimes put low-costs and a fast work done before long durability and artistic decoration.

– It is exactly the same as today. For example, you can see if a linen or silk fabric is better than another one. Even though plasters in Pompeii consist of exactly the same material, you can see that the craftsmanship is of a higher quality in a temple than in a simple private residence. On the walls of the temple, for example, the lime has no lumps, the plaster is better mixed and it is also applied in a thicker layer, Agneta Freccero explains.

The difference in quality may even be reflected in the same house. The cheapest plaster would do just fine in hallways, kitchens and bathrooms. In areas that were shown to visitors, there were plasters of better quality with more refined decorations.

In line with previous research, Agneta Freccero also found a clear chronology among the plasters in Pompeii. The samples she analyzed date from 300 BC to about 100 AD and are divided into nine different groups.

– You can see that there is a gradual development of the various plasters. They did not suddenly just change method from one day to the other, but they refined the methods for a long time, says Agneta Freccero.

Agneta Freccero hopes that the research method she developed while working with the material from Pompeii can be used as a model for other archeologists and conservators. Through microscope, she made an initial determination of plaster samples. These determinations were found to correspond very well with the much more sophisticated analysis of the material that later was made at a laboratory in Florence.

– It's satisfying that the two methods complement each other so well, and that you can reach so far with my simpler approach, she says.

A database covering houses, samples and types

The study presented in the Pompeian Plasters Database contains information about plasters used for wall decorations in Pompeii. The database has three sections: houses, samples and types. The earliest plasters identified are the ones who are in group 0 (zero) followed by eight more groups in chronological order.

The aim of the project was to study lime plasters to find a clear relation between typology and stratigraphy. The database includes photographs and measurement data, which contain information on blackness and colour, and if the material is volcanic, compact, porous, crystalline, etc. Data can be ordered via SND and require permission from the principal investigator at set occasions.          Plaster in the Basilica