When I started writing this column in 2022, I began with a fundamental method of looking at works of art. Over the first weeks, I discussed the basic building blocks of this approach and eventually I put a name to the approach – Formalism – and I summarised it. But alas, there is more to looking at a work of art than those elements of art and the principles of design which we discussed. When looking at art it also helps to know some things about the materials used, what we call the medium (or media when plural). Therefore, with specific reference to painting and drawing, it also helps to know some things about the kinds of marks different media can make. Meanwhile, in relation to sculpture it helps to know the possibilities and limits of different kinds of materials that may be used. Likewise, with ceramic, photography, etcetera. Therefore, having an idea of some of the technical possibilities and limits of different media can help inform a reading of work.