Wood grain

Wood grain is the longitudinal arrangement of wood fibers or the pattern resulting from such an arrangement. It has various derived terms refer to different aspects of the fibers or patterns. Wood grain is important in woodworking and it impacts aesthetics. Wood grain is the longitudinal arrangement of wood fibers or the pattern resulting from such an arrangement. R. Bruce Hoadley wrote that grain is a "confusingly versatile term" with numerous different uses, including the direction of the wood cells (e.g., straight grain, spiral grain), surface appearance or figure, growth-ring placement (e.g., vertical grain), plane of the cut (e.g., end grain), rate of growth (e.g., narrow grain), and relative cell size (e.g., open grain). The two basic categories of grain are straight grain and cross grain. Straight grain runs parallel to the longitudinal axis of the piece. Cross grain deviates from the longitudinal axis in two ways: spiral grain or diagonal grain. The amount of deviation is called the slope of the grain. In describing the alignment of the wood in the tree, a distinction may be made. Different tree species may have one of the following basic grain descriptions and types: straight - grain which runs in a single direction, parallel to the axis of the tree. spiral - grain which spirals around the axis of the tree. interlocked - grain which spirals around the axis of the tree, but reverses its direction for periods of years resulting in alternating directions of the spiral grain. On quartersawn surfaces the change in grain direction creates a ribbon stripe figure. wavy - grain which grows in a wavy fashion up the trunk; seen best in flatsawn sections of wood. irregular - grain that swirls or twists. It can be found in a number of different patterns. This can be caused by factors such as knots, burls or "crotch" wood - where large branches separate from the trunk. An important physical aspect of wood grain in woodworking is the grain direction or slope (e.g., against the grain).