A partition assembly comprising a partition matrix made up of intersecting first and second slotted partitions, each of the partitions having at least one slot and a rounded edge. The slots of the partitions are engaged with each other at a plurality of intersections. The partitions are made by rounding an edge of a multi-layered blank using a rotatable tool and then cutting the partition material to a desired size. Slots may then be formed in the edge sealed material.