Glossary

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Air-dried (AD)
Lumber or other wood products that have been either dried by exposure to natural atmospheric conditions outdoors or in an unheated shed or dried to equilibrium with the surrounding atmosphere. Moisture content of air-dried wood fiber depends on relative humidity, temperature, and length of drying period. Also referred to as air seasoned and contrasts with kiln-dried (KD) lumber.

Annual growth rings
The layer of growth that a tree puts on in one year. The annual growth rings can be seen in the end grain of lumber.

Board Foot (BF or BDFT)
Board Foot - A unit of measurement similar to square footage but takes into account the thickness of the wood, not just the surface area;

Width in inches x length in feet x thickness in inches (6/4s = 1.5'' ect.) / 12 = board feet.

Bookmatch
A term in veneering, where successive pieces of veneer from a flitch are arranged side by side. A properly done bookmatch will resemble a mirror image of the opposite side.

Boule
A log live sawn and kept together in the order of sawing.

Burle
The source of the highly figured burl veneers used exclusively for ornamental purposes, it is a bulge formed on the trunk or branches of a tree by abnormal wood formation.

Cant
Log that is squared on two or more sides.

Clear
Lumber or logs that are free or practically free of defects.

Crotch
In lumber, a piece of wood taken from the fork of a tree. Crotch Veneer is highly valued for its figuring.

Dressed Timber
Timber finished to a smooth surface on one or more surfaces.

Drying Defect
Any irregularity occurring in or on wood, as a result of drying, that may lower its strength, durability, or utility value. The following are some commonly encountered drying defects:

• Bow — The longitudinal distortion, flatwise, from a straight line drawn end to end of lumber
• Check — A lengthwise separation of wood that extends along the wood grain. It develops during drying and is commonly caused by differences in radial and tangential shrinkage or because of uneven shrinkage of the tissues in adjacent portions of the wood
• Collapse — The flattening of single cells or row of cells which occurs during drying of some species with very wet heartwood; it is often evidenced by a caved-in or corrugated appearance of the wood surface
• Cup — A distortion of a plank or board resulting in a troughlike shape with the edges remaining more or less parallel to each other
• Honeycomb — Internal splitting, often not visible at the wood surface, that develops during drying. It is caused by internal stresses or by the closing of surface checks
• Mineral Stain — An olive to greenish-black or brown discoloration believed to show regions of abnormal concentrations of mineral matter in some hardwoods. It is common in hard maple, hickory, and basswood. See also Mineral Streaks;
• Shake — A separation along the the grain, the greater part of which may occur at the common boundary of two rings or within a growth ring. It is usually considered to have occurred in the standing tree or during felling;
• Surface Checks — Checks that occur on the wood surface during seasoning; they may extend to varying depths into the wood;
• Twist — A distortion caused by the turning or winding of the edges of a board so that one corner is no more in the same plane as the other three;
• Warp — Any variation from the true or plane surface in a piece of wood that may occur during seasoning. It includes bow, crook, cup, and twist, or any combination thereof.

Earlywood
The less dense, larger celled, first formed part of a growth ring. Also called “springwood”.

Edge Joining
Smoothing and squaring the edge of a board so that it can be glued up squarely to another piece.

End Grain
The grain shown on a cross cut surface.

Face Veneer
High quality veneer that is used for the exposed surfaces on plywood.

Figure
Design or distinctive markings on the cut surface of wood produced by annual growth rings, rays, knots, deviation from regular grain such as interlocked and wavy grain, and irregular discoloration. It may also refer to such decorative designs in wood that make them highly desirable in the furniture and cabinetmaking industries. The following are some commonly encountered types of figure:

• Bird's-Eye Figure — Figure on the plain-sawn and rotary cut surface of wood showing many small circular or elliptical areas resembling a bird's-eye. It is caused by local fiber distortions and is usually present in hard maple.
• Dimple Figure — Indentations, caused by localized fiber distortions, that produce a figure resembling dimples on the tangential surface of sawn lumber or rotary-cut veneer.
• Fiddleback — Figure in timber or veneer produced by small, regular undulations in the grain.
• Mottled Figure — A disjointed stripe figure interrupted by irregular, horizontal waves in the wood grain.
• Quilted Figure — Blister-like figure sometimes found in bigleaf maple (Acer macrophyllum).
• Ribbon Figure — Figure consisting of light-induced interchanging darker and lighter bands. It is obtained when wood with Interlocked grain is quarter-sawn or sliced. It is also referred to as stripe.
• Roey Figure — Figure formed by relatively short stripes (< 1ft long) on the quarter-sawn face of wood containing interlocked grain.

Flitch Matched
Sequentially sawn lumber from the same log.

Grade
The designation of the quality of a piece of timber or other manufactured wood products in accordance with standard rules. The most commonly encountered grades are as follows:

• Common — Lumber with obvious defects.
• FAS — 1st and 2nd. Mixed domestic hardwood lumber grade is for the highest grade of hardwood lumber. In most species a board must be 6'' or wider, 8' or longer. Walnut and Butternut are the exceptions.
• Select — A high grade of lumber that allows few defects.

Grain
The size, alignment, and color of wood fibers in a piece of lumber. Common types of grain are as follows:

• Closed Grain — Wood with narrow, barely visible annual rings. It is also used to describe wood with small and closely spaced pores.
• Crossed Grain — Wood in which the direction of alignment of the fibers deviate from a line parallel to the sides. Crossed grain may be either diagonal or spiral or a combination of the two.
• Curly Grain — Wood with distorted fibers resulting in a curly appearance as in bird's-eye wood. The area covered by each curl may vary up to several inches in diameter.
• End Grain — The grain as seen on the cross-section of a piece of wood.
• Fiddleback Grain — Figure produced by a type of fine and wavy grain found in certain species such as, maple. Wood with such figure is traditionally used for violin backs.
• Interlocked Grain — Grain in which the direction of the fibers follow first a left- and then a right- handed spiral, and then alternate the spiral direction every few years. Such wood is very difficult to split radially, although it may split fairly easily in the tangential direction.
• Irregular Grain — Figure produced by the contortion and twisting of fibers around elements such as knots, in a piece of wood.
• Spiral Grain — Wood in which the fibers follow a regular spiral direction (right-handed or left-handed) around the trunk of the tree instead of the normal vertical course. It is a form of cross grain.
• Straight Grain — Wood in which the direction of fiber alignment is parallel to the main axis of the piece.
• Wavy Grain — Wood in which the collective appearance of the fibers presents a regular form of waves and undulations.

Green Wood
Freshly sawed or undried wood which still contains the moisture that was present in the standing tree.

Growth Ring
The layer of wood growth formed by a tree during a single growing season. In many tropical species, annual growth rings are hardly discernible.

Hardwood
A general term for timber of broad leafed trees classified botanically as Angiosperm. The term has no reference to the relative hardness of the wood.

Heartwood
The wood making up the centre part of the tree, beneath the sapwood. Cells of heartwood no longer participate in the life processes of the tree. Heartwood may contain phenolic compounds, gums, resins, and other materials that usually make it darker and more decay resistant than sapwood.

Hewn timber
Timber with or without wane, finished to size with hand tools such as an axe or adze.

Hewn timber
Timber with or without wane, finished to size with hand tools such as an axe or adze.

Kiln Dried (KD)
Describes lumber that has been dried in a kiln (as opposed to being air dried).

Late Wood
The denser wood formed during the later stages of growth of each annual ring. Also called “summerwood”.

Moisture Content
The weight of moisture contained in a piece of timber expressed as a percentage of the oven dry weight.

Movement
The extent of expansion and contraction which occurs with dried wood as its moisture content responds to changes in relative humidity in service.

Nominal
The name for the size of a piece of lumber, not the actual measurement of that piece (What we call a 2x4 is actually a piece of lumber measuring 1-1/2'' x 3-1/2'').

Pith
The soft core in the center of a tree trunk.

Plain
A ribbon like figure caused by the strands of cells which extend across the grain in quarter sawn lumber.

Plain-sawn
Also referred to as flat-sawn, it describes wood that is sawed so that the growth rings meet the face in any part at an angle of less than 45 degrees.

Quarter-sawn
A method of cutting lumber where the annual rings are relatively perpendicular to the face of the board. Quarter-sawn lumber tends to be more dimensionally stable than other forms of lumber, such as plain-sawn.

Rough sawn
Surface condition of wood as it leaves the saw, not dressed or final sawn.

Sap Wood
Outer layers of wood which, in a growing tree, contain living cells and reserve materials such as starch. Under most conditions the sapwood is paler in colour and more susceptible to decay than heartwood.

Slab
A broad flat piece of wood cut directly from the log, often with bark on both edges.

Softwood
Generally lumber from a conifer such as pine or cedar. The name softwood does not refer to the density of the wood. There are some hardwoods, such as Balsa, which are softer than some softwoods, like Southern Yellow Pine.

Surfaced
Lumber that has gone through a planer so that its sides are smooth and uniform in size.

Veneer
A thin layer or sheet of wood.

Veneer-core Plywood
Plywood made from three or more pieces of veneer glued up in alternating grain patterns.

Wane
The natural live-edge of a tree remaining along the edge of a board.