In this paper, I discuss how ‘sense’ is made in art therapy regarding three uses of the term: that of ‘meaning’, ‘somatic experience’ and the capacity for ‘sensing’. I suggest that the patient in an art therapy session produces actions and artefacts which come into contact with the mind of the therapist/group. This allows for a dream to be generated between the creator and the observer, that the artwork can tell us something about internal mental states within the creator. I propose a theory of observation by application of an Aesthetic Grid - an adaptation of Bion's Grid of genetic epistemology. This is an attempt to bring together ‘three waves of art therapy theory and practice’, and incorporates the function of the art object, as well as the phases of art making and looking/talking. The Aesthetic Grid is not intended for use in sessions but rather to be utilized after the event, in order to reflect upon the status of the ‘art-psychotherapy object’ - the totality of the triangular relationship, creator-artwork-viewer, and whether this constitutes development and growth or its inverse.