Opus albarium

It is used in the interiors of houses, consisting of a special stucco incorporating marble dust, then beaten compact with rammers to finish the interior walls and ceilings of houses.

[1] Opus albarium is similar to modern stucco.

It was often a final layer, with no intention of painting the wall afterwards.

The slaked lime was soaked in water, then struck through with a tiller.

[3] Varro states that such wall coatings make buildings cooler.