As the name suggests, an unlined bra does not contain any lining or padding in the cups whatsoever. So rather than sculpting your breasts, unlined bras will allow your breasts’ natural shape to shine. A unlined bra will not hold it's cup shape when off of the body as a lined or contour bra will. One reason they’re appreciated by many is that they’re incredibly lightweight. Some styles also have a subtly sexy appeal due to the semi-sheer cups.