Abstract: A structure for supporting a plurality of objects having cylindrical characteristics. The structure includes a first side and a second side, the first side having at least two rib structures spaced apart from one another by valleys. The rib structures are formed as an alternating series of arches and depressions. The depressions define the retaining position for the objects. The arches include lands with cavities that enhance the structural characteristics of the ribs. The second side includes three or more spaced rib sections that are formed as an alternating series of peaks and depressions. The depressions of the second side correspond to the depressions of the first side. The rib sections of the second side correspond to the valleys of the first side. The arches of the first side are relatively higher than the equivalents in the prior art in order to provide greater surface area contact with the cylindrical objects to be retained.