First things first: satin isn’t a fabric. Satin refers to the weave of a fabric, meaning there’s silk satin, polyester satin, nylon satin…. (If you want to veer into serious fabric-nerd territory, there are different kinds of satin, too, such as charmeuse, duchess and panne, but there will not be a test later!) There are also different styles of pillowcase closure. If you have sensory sensitivity, opt for an envelope style—the pillow slides in like a letter into an envelope—or a hidden zipper, which keeps the metal inside the case and away from your face.