Freshman move-in has a way of turning a short packing list into a very expensive week. It is the Twin XL bedding that actually fits, the laundry gear you can carry down the hall, and the small-room basics that keep you from buying replacements at campus-store prices later. Prices are accurate at the time of publishing but may vary by store or sell out quickly. Mainstays Twin XL cotton-blend sheet set Image Credit: Walmart Dorm mattresses are usually Twin XL, which is just different enough from a regular Twin to make bringing sheets from home a bad gamble. You get a fitted sheet, flat sheet, and standard pillowcase in the correct 39-by-80-inch mattress size.