You can purchase door skin panels online from companies such as WoodChipLumber.com and PVC-Shutter.com. Wood door veneer is also available online at BirchwoodBest.com. Birchwood Best produces wood door skins from a variety of tree species such as ash, cherry, walnut and birch.
Birchwood Best constructs two- to three-ply wood door skins in sizes as large as 49 inches by 121 inches. Wood Chip Lumber is another company that produces plywood door skins. Wood Chip Lumber's door skin products are one-eighth of an inch thick and are available in bundles of 10 sheets of stripes that are 2 inches wide and 8 feet long.