Roman plasterwork was applied in layers, and in first layer (which is quite rough) a diamond pattern is scratched. This is to increase the adhesion of the next layer (also known as the key). This is also true of lime plasterwork done through the ages.
As far as I can see only the first layer with the diamond pattern is visible one the left wall. The other layers may have not survived. Why would you bother to create a diamond pattern if you're not going to put more layers on?
In fact, the wall at the far end does show more layers, and also some decoration right in the the middle.
As far as I can see only the first layer with the diamond pattern is visible one the left wall. The other layers may have not survived. Why would you bother to create a diamond pattern if you're not going to put more layers on?
In fact, the wall at the far end does show more layers, and also some decoration right in the the middle.