While most decorative panel manufacturers in North America will offer proprietary or custom grades, the consensus grading standard is ANSI/HPVA HP-1-2004, American National Standard for Hardwood and Decorative Plywood. This document establishes unique characteristics for each species of wood veneer in face grades of AA, A, B, C, D & E and in back grades of 1, 2, 3 & 4. This standard also provides standards for core grades and adhesives, and is a valuable resource for anyone buying or specifying decorative wood panels. ANSI/HPVA HP-1-2004 is available from the Hardwood Plywood & Veneer Association, P.O. Box 2789 Reston, VA 20195, 703-435-2900.
What follows is a general description of the grade categories from the HPVA. For details about individual species refer to the standard.
FACE GRADE APPLICATIONS
- AA: a premium face grade for exclusive uses such as architectural paneling and interiors, case goods and quality furniture.
- A: where AA is not required, but excellent appearance is still important.
- B: where the natural characteristics and appearance of the species are desirable.
- C: allows for unlimited color and increased natural characteristics and is perfect for applications where an economical panel is needed.
- D&E: provide sound surfaces but allow unlimited color variation and allow repairs in increasing size ranges. Applications: where surface will be hidden or a more rustic character is desired.
BACK GRADE DESCRIPTIONS
Back Grades are designated by numbers 1,2,3 and 4. Requirements of Grade 1 are most restrictive, with Grades 2,3 and 4 being progressively less restrictive. Grades 1 and 2 provide sound surfaces with all openings in the veneer repaired except for vertical worm holes not larger than 1.6mm (1/16"). Grades 3 and 4 permit some open defects, however grade 3 can be obtained with repaired splits, joints, bark pockets, laps and knotholes to achieve a sound surface if specified by the buyer. Grade 4 permits knot holes up to 102mm (4") in diameter and open splits and joints limited by width and length.