This chapter focuses on the nature of cognitive artefacts and the ways in which they provide information of the said kind and thereby serve cognitive functions of the said kind. It argues that there are two fundamental ways in which cognitive artefacts may convey information about a given subject matter: the information they provide is either convergent with, or isomorphic to, natural information that a perceiving subject could collect in his or her environment. This distinction will help to generate a more differentiated picture of the nature of cognitive artefacts than the conventional reality/virtuality distinction. It will be particularly relevant with respect to artefacts that integrate simulated elements into the perception of an environment, as in "mixed" or "augmented" realities. The chapter explores the interplay between cognitive artefacts and informational environments on a more general level. Finally, it shows pictorial forms that form an interesting example of a cognitive artefact.