Cotton is a type of soft, breathable fabric made from fibers of the cotton plant. It is the most widely used natural-fiber cloth in clothing today. It is used for practically all kind of clothing: t-shirts, trousers, dresses, skirts, underwear, etc.
Cotton and fetishism
In the spanking scene, there is in fact such a thing: many spankos cherish the "domestic" look and feel, rather than the stereotypic BDSM-style (black leather, latex and harnesses), and often have a preference for "mainstream" clothing made from simple cotton, such as schoolgirl uniforms and white cotton underwear, especially if such a garment looks traditional (vintage, old-fashioned).
However if a real vintage look and feel is desired, linen might be the material of choice.