Burl: A burl is a swirl or twist in the grain of the wood which usually occurs near a knot but does not contain a knot. Those containing sound centers are admitted in the cutting except when otherwise specified.
Check: A lengthwise separation of the wood that usually extends across the rings of annual growth and commonly results from stresses set up in wood during seasoning.
Bird Peck: A patch of distorted grain resulting from birds pecking through the growing cells in the tree and sometimes containing a hole and/or ingrown bark.
Pin Knot: A knot which does not exceed 1/8” in average diameter.
Seasoning (Kiln-Dried): Dried in a kiln with the use of artificial heat.
Shake: A separation along the grain, the greater part of which occurs between the rings of annual growth.
Split: A lengthwise separation of the wood, due to the tearing apart of wood cells.