Wood Terminology

AIR DRIED – Air-dried is wood that was not dried in a kiln.  The moisture content of air dried wood is affected by where the wood is located.  Wood on the coast or in a humid environment will have a higher moisture content than wood in a dry area such as Arizona or New Mexico.

BOARD FOOT (BF) – Standard unit of lumber measurement equal to 144 cubic inches of wood.  For example, all of these boards would have one board foot of wood:  12 x 12 x 1 inch thick, 3 x 48 x 1 inch thick, 144 x 1 x 1.  Board footage is 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 board feet.

BOOKMATCHED – Adjacent pieces of wood from a log or cut that are opened like a book.  When two bookmatched pieces are used together, it looks like a mirror is between them, and the woods match where the splice or glue joint is located.  The bookmatched 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.

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.  Burls usually have swirls, twists, or distortion in the grain of the wood, which usually occurs near a knot or crotch.

CATHEDRAL – A grain appearance characterized by a series of stacked and inverted “V” or cathedral patterns common in plain-sliced (fiat-cut) veneer.

CENTERHEART or PITH – The center of a tree where there is a small hole that seems to be filled with a material soft like cork.  Many posts and large pieces of wood have centerheart or pith.  All trees have centerheart or pith.  This is where you start counting growth rings in the center of the tree to determine the age.

CHECKS – Small slits running parallel to grain of wood, caused chiefly by strains produced in seasoning.

COCOBOLO KING – The highest grade of cocobolo.  Hand-picked for figure and specific applications in the finest woodworking projects. 

CROSS GRAIN – Working perpendicular to the grain.

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.

END GRAIN – The grainsat the end of a piece of wood that are perpendicular to the surface.   End grain is the opposite of long grain or the long fibers in wood that grow vertically in the first big log of a tree.

FIGURE – The pattern produced in a wood surface by annual growth rings, rays, knots, deviations from natural grain such as interlocked, curly and wavy grain, and irregular coloration.

FINGERJOINT – A series of fingers machined on the ends of two pieces of wood to be joined, which mesh together and are held firmly in position with an adhesive.

GRAIN – The direction, size, arrangement and appearance of the fibers in wood or veneer.

GREEN – Freshly sawn lumber.

HARDWOOD – General term used to designate lumber or veneer produced from temperate zone deciduous or tropical broad-leaved trees in contrast to softwood, which is produced from trees which are usually needle bearing or coniferous. The term does not infer hardness in its physical sense.

HEARTWOOD – The inner core of a tree.  This wood is usually much darker and denser than the sapwood.  The heartwood of a tree is the center, non-active or dormant part of a tree generally distinguishable from the outer portion (sapwood) by its darker color.

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

JOINT – The common edge between two adjacent materials in the same plane.

KILN DRIED – Kiln Dried for outdoor use is typically 10-12% moisture content.  Kiln Dried for indoor use is typically 6 to 8%.

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.  A knot is a cross section of tree branch or limb with grain usually running at right angles to that of the piece of wood in which it occurs.

KNOTHOLES – Openings produced when knots drop from the wood in which they were embedded.

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

QUARTERSAWN – Growth rings in quarter-sawn wood run parallel along the entire board.   Quartersawn 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, quartersawn 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.  Quartersawn wood has a straight grain appearance achieved through the process of sawing the timber with vertical growth rings.


S4S – Surfaced four sides or edged and planed

SAPWOOD – The living, outer portion of the tree, usually distinguishable from the heartwood by its drastically lighter color.   Sometimes referred to as sap.

VENEER – A thin sheet of wood, rotary cut, sliced, or sawed from a log, bolt, or flitch.  Veneer often refers to thin slices of wood, usually ¼ inch or thinner that are used in the production of fine woodworking pieces.  Veneers are also used to increase the strength of wood and to produce flat panels such as doors, tops and side panels for cabinets and parts of furniture.

WANE – An edge of a sawn board where the bark or surface of the trunk still remains.  Wane comes from the curved, outer portion of a log.  This is also called natural edge.