This chapter focuses on the significance of skin in neoclassical art and aesthetics. The most distinctive features of neoclassicism - an emphasis on the contour and a preference for more finished surfaces - are understood as elements crucial for the visual formation and understanding of the human body, its surface and borderlines. The culture of neoclassicism, extending well beyond the realm of art and art discourse, was generally characterised by a heightened concern with the shaping of the body and the safeguarding of its boundaries. Skin as the body's physical demarcation, was increasingly perceived not merely as an envelope and organ, but as the boundary of the self. The chapter considers the new attention to skin and contour in late eighteenth-century French art discourse, in particular in Watelet's and Levesque's Dictionnaire des beaux-arts. It equally looks at the discussion of membranes and the definition of skin as 'sensitive limit' in the works of anatomist Xavier Bichat and analyses a set of portraits by Jacques-Louis David painted in the aftermath of the French Revolution.