Select: A grade that is truly selected which allows only very small tight knots and no deviations in the joint, rabbets, or hand holds. Our woodenware is manufactured from hand selected Ponderosa pine. Each board has been carefully moisture-metered to assure its proper moisture content before it is precision milled into the finished product. All our supers have pre-drilled holes for nails to prevent splitting during assembly. Handholds are taper cut for easy gripping - Moisture Metered before cutting to prevent warping - Uniform Interlocking Joints for strength - Ponderosa pine from the Northwest, the best wood for the job - Uniform Frame Rests provides the proper Bee Space.Paint the outside of the super only.