An apparatus structured to contact external tissue, such as skin, of a user includes an elastomeric contacting portion that is structured to directly engage the external tissue. The contacting portion has an engineered surface (64A, 64B) that includes a plurality of non-random, predesigned surface features (70, 74B, 76B, 78B) designed to reduce friction and improve user comfort. In one implementation, the pitch (P) between each immediately adjacent pair of the surface features (70, 76B) is less than or equal to a predetermined maximum pitch value, and the height (H) of each of the surface features (70, 76B) is less than or equal to a predetermined maximum height value.