The face of a plank may contain prominent color variation, unlimited burls, brown streaks, open or filled knots of any size, and wormholes. Open splits and knots create an effect of antique wood and emphasize authentic oak texture. “Character” grade is used to classify wide plank fixed length flooring 7½X7 inches (190X2100 mm) – due to the larger surface area, a face of plank may contain a wide range and number of burls, streaks, knots, wormholes, etc.