The pasting theorem showed that pasting schemes are useful in studying free!-categories. It was thought that their inflexibility with respect to composition and identities prohibited wider use. This is not the case: there is a way of dealing with identities which makes it possible to describe!-categories in terms of generating pasting schemes and relations between generated pastings, i.e., with pasting presentations. In this chapter I develop the necessary machinery for this. The main result, that the!-category generated by a pasting presentation is universal with respect to respectable families of realizations, is a generalization of the pasting