Thanks Jonathan. The top and bottom layers are 1/8 in. thick solid red oak "re-sawn" layers that can be sanded, stained, and finished like real wood....because they are real wood. These are not the paper-thin veneers made famous on assembled furniture. The engineered core, along with the solid oak top and bottom layers, produces a stable stair tread that resists warping, twisting, and checking. You also get even grain and color matching as well.