Wood Terminology

BOARD FOOT (BF)

Standard unit of lumber measurement equal to one foot square by one inch thick (144 cubic inches). Calculated by multiplying length by width by thickness in inches and dividing by 144. Example: 2 x 3 x 36"=216 divided by 144=1.5 bf.

AIR DRIED

Air-dried is typically 15% moisture content.

KILN DRIED

Kiln Dried for outdoor use is typically 10-12% moisture content.

GREEN

Freshly sawn lumber.

BURL

A unique, knotty growth that usually develops at the base of certain trees. A cut through a burl reveals tight bunches of small knots.

FIGURE

The pattern produced on a board surface by prominent rays or deviation from regular grain. Types of figure include: birds-eye, burl, curl, crotch, curly, quilted, and ribbon stripe.

BOOKMATCHED

This is done by cutting a piece of wood in two so that the horizontal grain appears to create one continuous line when matched up against one another, and so that the lines are perpendicular to the seam, similar to a book. The effect can range from extremely subtle so that it appears to be a single piece of wood, to dramatic effects with very wavy grain showcased in high-end guitars.

SAPWOOD

The outer portion of the tree, usually distinguishable from the heartwood by its drastically lighter color.

HEARTWOOD

The inner core of a tree, much darker and denser than the sapwood.

CROTCHWOOD

The section of a tree where a branch divides from the trunk, or the trunk divides in two, typically an area of unique and complex grain.

QUARTER-SAWN

Growth rings in quarter-sawn wood run uniformly parallel along the entire board the wood does not shrink and expand with seasonal variation in moisture as much as flat sawn wood. In addition because of the orientation of the growth rings, quarter-sawn wood is less prone to shrinkage, twisting, cupping and in many cases rot because sapwood is easier to isolate in manufacturing process. In acoustic guitars, quarter-sawn wood is often used, especially for the sides that must be steam bent to produce compound curves.

PLAIN-SAWN

Lumber is sawn so that the annular growth rings are parallel to the face of the board.

VENEER

Refers to thin slices of wood, usually thinner than 3 mm (1/8 inch), that are usually glued and pressed onto core panels (typically, wood, particle board or medium density fiberboard) to produce flat panels such as doors, tops and side panels for cabinets and parts of furniture.

INTERLOCKED GRAIN

Grain that has multiple longitudinal directions in alternating layers, typical of many tropical hardwoods.

END GRAIN

The grains at the end of a piece of wood that is perpendicular to the surface.

CROSS GRAIN

Working perpendicular to the grain.

KNOTS

Caused by a dead branches that were not fully integrated into the tree before it was cut down. A loose knot cannot be relied upon to remain in place in the piece. A tight knot fixed by growth or position in the wood firmly retains its place in the surrounding wood.

WANE

An edge of a sawn board where the bark or surface of the trunk still remains.