Mercier Element Collection. Hickory Engineered, Authentic Grade. This grade is high in tonal contrasts, showcasing the full range of vivid natural colors found in the species. Pronounced variation between boards. Sound knots and knots filled with wood putty (including slight openings or depressions) are accepted without limitation. Openings in and around knots are accepted. Mineral streaks are accepted without limitation. Surface splits and checks and end splits are accepted in this grade. Other characteristics: Varnish cracks around character marks are accepted in this grade.