This particular style of engineered walnut flooring is known for its grain pattern complimented with natural wood knots. In this fashion, the natural oiled American walnut flooring provides warm blonde and chocolate tones, helping to define space with depth and tone. It offers a better wear layer than the 15mm thick alternative. The board structure is made up of a 6mm layer of walnut, bonded to a 14mm 10 layer birch ply. By oiling the wood, the natural tones are further enhanced, providing a higher quality finish and walnut flooring product.