Almost all mattress pads use elastic to connect to the bed and stay in place. The most common way that this elastic is deployed is by sewing it into the perimeter of the pad. A skirt or side panel goes over the sides of the mattress, and the skirt has elastic placed either in the corners only or in a continuous band that goes around the full hem. In this way, these mattress pads resemble a fitted sheet. In some cases, a mattress pad does not have a skirt or side panels and uses elastic straps in each corner to go under the mattress and hold the pad in place. Pads with this design are often prone to shifting around and needing to be reattached.