The most recent theory proposed by Peter Lacovara as to the purpose of the "mutilations" is that they are guidelines used by the sculptor in the creation of the reserve head. He proposes that a closer examination of the evidence points to all of the lines being carved onto the reserve heads as being done prior to their completion rather than afterwards. As proof he points out that in the most complete examples, the mutilations are minor or absent, and on others it is clear that what grooves were made were subsequently smoothed down, rather than being the fresh cut that would be expected if they were inflicted after their creation. There are other Ancient Egyptian unfinished sculptures where guidelines for the sculptor can be seen, usually painted onto the hard stone. Lacovara believes that paint would have easily rubbed off of the relatively soft limestone that was used, and so the sculptors carved the guidelines instead. These guidelines were then polished away, and in the cases where they were not removed completely were covered by plaster which has since fallen away. Plaster would also have been used to cover up any mistakes that the sculptor had made, such as with the example of heavy plaster seen on one of the reserve heads in Cairo (60003) where the eye has been recarved. The damage seen to the ears of many of the reserve heads is thought to be due mainly to rough handling by tomb robbers. All of this would support the original theory that the reserve heads were designed as alternate places for the soul of the deceased to inhabit.