Abstract: A fiberboard mat, whether made by a dry process, a wet process, or dry/wet combination thereof, can be consolidated against a fiber displacement die, contacting and penetrating into a back major surface of the fiberboard mat, to provide fiber-void regions, to achieve a lighter panel, while achieving fiber savings and while maintaining structural integrity and substantially uniform density in the fiber-containing regions. The fiber displacement die includes a plurality of pointed projections that serve to laterally displace fibers, during consolidation of the mat. The displaced fibers are held in their displaced position during the consolidation of the fiberboard mat to provide a consolidated panel having substantially uniform density, or at least a substantially more uniform density, that varies substantially in caliper due to the fiber-void regions.