(The Differences That Made the Difference) Diverse materials are used to match the sensibility of your nether parts these thongs touch. For the crotch, sheer cotton is used to contra this area's predisposition to venereal discomfort while nylon is added to the body to confer steadfastness against shrinkage and to form a thin layer of breathable mesh to keep the whole area dry and clean. Icing on the cake? The pantie lines of these undies still stay invisible despite all the complex materials.