Burls - Tiny swirls or twists in the grain.

Character - Details seen in the wood such as streaks, knots, and wormholes.

Clear - Clear flooring has no visual blemishes or knots.

Formal - Styles reflected by rooms/houses which are not casual.

Grade - A standard category defining the general appearance of the wood.

Grain - The parallel alignment of wood fibers.

Heartwood - Wood growing near the center of the tree.

Informal - Styles reflected by rooms/houses which are casual.

Knot - Round, dark patches left by branches growing through the grain of the wood.

Sapwood - Wood growing near the outside of the tree.

Select - Select flooring has some small knots and very little dark graining.

Spalting - Splotches left from bacteria which is killed during processing.

Streak - A dark line following the grain.