Mold that grows in warm and moist area, usually poorly ventilated. Discoloration of wood. Can be cut off, placed out of sight, or concealed with a dark stain . Bow A curve along the face of a board that usually runs from end to end. Usually moisture evaporation from one side and not the other.
Stock is difficult to work with and cut.
Checks or Splits Picture Breaks at the end of a board that run along the grain. Checks and splits are usually restricted to the end of a board. Can effect the strength and appearance of the board. Should be cut off or worked around. Crook Warping along the edge from one end to the other.