Lumber Core Plywood
A lumber core plywood has a core that is made up of actual lumber with a piece of wood in the middle with two thinner pieces of wood veneer on each of its sides.
The outer surface of a lumber core plywood is typically birch, maple, or oak while the inner core is a softwood. It has bending strength and screw-hold ability. The combination of hardwood and softwood makes this a durable and versatile type plywood for building shelves, cabinets, and closet doors.