A bark-filled blemish in the board.
The decomposition of wood substance by fungi.
The early stage of decay that has not proceeded far enough to soften or otherwise perceptibly impair the hardness of the wood. It is usually accompanied by a slight discoloration or bleaching of the wood.
One 1/4 inch in diameter or larger.
The small soft core occurring in the structural center of the log.
A knot that does not exceed 1/4 inch in average diameter in its sound portion or 1/8 inch in average diameter in its unsound portion.
In hardwoods, the word stain is used to describe the initial evidences of decay.
A knot that is solid across its face, as hard as the surrounding wood, and shows no indication of decay. Sound knots include star checked knots.
A lengthwise separation of the wood, due to the tearing apart of wood cells.
A distortion of a board in which there is a deviation edgewise from a straight line from end to end of the board.
Bark or lack of wood.
A separation along the grain, the greater part of which occurs between the rings of annual growth.
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.