The drawing of 'outlines' can be shown to be dependent upon the bounding edge aspect of visual cognition, which is a principal means of discerning 'identity' from other features of experience in the visual field. Visual 'signatures' can be noticed when using techniques for the scientific visualization of data. Using examples from an ongoing art-science project between the Faculty of Arts and Architecture (Brighton) and the Meteorology Dept at the University of Reading, the paper will explore the boundary between the 'rational' and the subjective, and between the representation of knowledge and