Like greek, roman sexual territory is a foreign domain. There is pertinent information about roman sexual matters in all sorts of ancient literature legal texts, history, poetry, and political discourse. Ancient erotic handbooks (often illustrated) have not survived. As well, we have artistic representations and objects (vases, lamps, mosaics) depicting sexual scenes. The visual record is far richer than the textual record. All social classes (elite, free, freed, slave) and both genders viewed erotic objects: the visual representations appeared at all levels of society. Fresco painting was the technique of trapping pigments in the lime mortar before it set, to ensure the decoration had a long life (not as long as fired pottery, which was virtually indestructible). Thus the painter works with mortar that is still wet, rendering would be done in small sections starting from the top of the wall. Sometimes details were added after the mortar was dry.