Abstract: A mattress overlay consisting of two pieces of fabric joined along the longitudinal, or head to foot, edges and then joined transversely, from side to side, at predetermined distances along the longitudinal axis forming lateral, closed interior cell spaces. In the preferred embodiment, the joining method along at least one of the longitudinal edges uses openable and recloseable cooperating hook and loop pressure strips to allow access to the individual cells after manufacture. To provide even support throughout the resting area, the interior cell spaces are partially filled with a flowable filler material of Buckwheat hulls or a mixture of Buckwheat hulls and any other compatible material. The preferred embodiment allows resting comfort to be customized by adding or removing flowable filler from individual cell spaces as needed. The preferred embodiment has half of an openable and recloseable fastening device joined along longitudinal edge to allow attachment of two or more mattress overlays.