Recently I read a book about dirt. Not the kind of dirt that I as an archaeologist have to deal with, but more the philosophical kind. Mary Douglas describes in her book "Purity and Danger: An Analysis of Concepts of Pollution and Taboo" how what is considered to be unclean is culturally dependent. The whole book is interesting in itself, but I am concerned with the cleanliness of 3D reconstructions and how unclean they actually need to be.