Cotton and cotton blends dominate the market, the most common blend being cotton/polyester. Cotton provides absorbency and a soft hand, while polyester adds durability and wrinkle resistance.^[2] Other common fibers used in the manufacturing of bed sheets include linen, silk, Modal and bamboo rayon, lyocell, Microtex or Microfiber, and polypropylene. Polypropylene (olefin) is a hypoallergenic spun-bound material produced at a low cost and typically used in emergency shelters or hospitals as disposable sheeting.

Most sheet sets typically include a flat sheet, fitted sheet, and one or two pillowcases. There’s not much need for wondering if you need a flat or fitted sheet for this reason — both are useful and usually come as a package deal. Some other sheet sets, like those Casper offers, also include a duvet cover.