Figure

Figure is the decorative visual pattern a board's wood fibers create, distinct from grain (which describes fiber direction) -- a board can have perfectly straight grain and still show dramatic figure, or vice versa. Curly (fiddleback) figure comes from fibers that wave gently and consistently; quilted figure from a more random, bubble-like waviness; burl figure from a chaotic tangle of small knots and grain distortion around a tree's burl growth.

Figured lumber is prized for how it plays with light -- the same board can look light or dark depending on viewing angle, an effect called chatoyance -- but that same wavy grain that creates the figure also makes the board harder to plane and finish cleanly without tearout, since the grain direction is constantly changing.