The fabric covering the mattress is referred to as what?

The fabric covering the mattress is known as ticking. Ticking is a type of closely woven fabric that is often used as a durable outer shell for mattresses. It is designed to hold the filling material in place, while also providing a protective layer that adds to the comfort and longevity of the mattress. Ticking typically comes in various patterns and colors and is usually made from cotton or a cotton-polyester blend, which helps to prevent the filling from escaping and mitigates wear and tear.

Other options, such as coverlet, bedspread, and comforter, refer to different types of bedding accessories used for decorative purposes or additional warmth. A coverlet is a lightweight decorative cover, often used for layering, while a bedspread is an all-encompassing cover for the bed that extends to the floor. A comforter is a thick and fluffy cover filled with materials like down or synthetic fibers, aimed primarily at providing warmth. These terms do not describe the functional fabric that makes up the protective covering of the mattress itself, which is why ticking is the correct choice.