Recent stereological methods are available for estimating the number and size of arbitrary particles or voids in a material very efficiently and in an unbiased manner, with the only assumption that particles must be identifiable on serial sections or confocal planes. However, applications of these methods have been published mainly in a biomedical context. The purpose of this paper is to emphasize the fact that stereology is sampling in 3D and its principles remain valid and applicable in no matter what context. As a working example we have chosen the pore population of a sand cast aluminium alloy. The implementation of some of the most relevant stereological tools, notably the disector and the selector, is thereby illustrated.