Mattress systems and methods for their construction are provided. One such mattress includes a first mattress core and a second mattress core positioned on top of the first mattress core. A border material extends along an outer first edge of the first mattress core and along an outer second edge of the second mattress core. The border material has an intermediate portion which extends between the first and second mattress cores and is coupled to at least one of the first and second mattress cores, and in some aspects to both cores.