yes, but I either rip them on the table saw from pine or buy up old wooden blinds, I picked up 6 blinds at the local boot fair for £15 81x 1" slats per blind, works out at pence per plank. blind slats do need to have the finish sanded down to allow glue to stick properly.
plywood wont give you a lot of sanding before you get to the layer beneath though.