This is a 1/4" thick unfinished maple plywood in 1" x 4" section. This sheet is a B4 grade. Front face is a B grade that is a smooth sanded and clear face. There may be an occasional minor blemish on the B face. Back side is a 4 grade that will be of same or similar wood but may have filled knots, veneer joints or seams. This plywood is a stain grade one side. This plywood has 3 plys.