It's reinforced with Luan Plywood, which is quite strong, light weight and very sturdy. Keep in mind that an entire 4X8-foot sheet of 1/4-inch luan plywood only weighs 20 pounds. Most travel cases made from plywood are constructed from 1/2-inch thick plywood, which weighs about 42 pounds for a 4X8 sheet, depending upon the grade. Higher grades weigh slightly more because of the increased amount of glue used in attaching the layers.

The Guardian Case I just purchased is reinforced with 1/4-inch plywood and weighs next to nothing.

Good Luck,

Gary