Unfinished Walnut flooring is available in a variety of widths and grades in both solid and engineered plank. This photo features Solid 3/4" Walnut, Natural Grade. Unfinished Walnut Natural Floor Species Walnut Width (s) Any Specific Width or Combination 4"-12" Construction Engineered & Solid Thickness 3/4" & 5/8" Grade Natural Grade (1 & 2 Common and Better) Installation Nail, Glue, Float http://www.heidelbergflooring.com/all-hardwood-floors/prefinished-flooring/type-of-finish/unfinished/american-Walnut-natural-unfinished-solid-engineered-hardwood-flooring