Mercier Hard Maple Authentic Grade. This grade is high in contrasts, reflecting the full range of vivid natural tones found in the species. Moderate to 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. Surface splits and checks and end splits are accepted in this grade. Mineral streaks are accepted without limitation. Varnish cracks around character marks are accepted in this grade.