Balance Match - Two or more veneer components or leaves of equal size to make up a single face.
Banding - Portion of wood extending around one or more sides of plywood panels.
Book match - Adjacent pieces of veneer from a flitch or log are opened like a book and spliced to make up the face with matching occurring at the spliced joints (see Figure 1 for illustration). The fibers of the wood, slanting in opposite directions in the adjacent sheets, create a characteristic light and dark effect when the surface is seen from an angle.
Burl, conspicuous - A swirl, twist, or distortion in the grain of the wood, which usually occurs near a knot or crotch. A conspicuous burl is associated with abrupt color variation and/or a cluster of small dark piths caused by a cluster of adventitious buds.
Burl, blending - A swirl, twist, or distortion in the grain of the wood which usually occurs near a knot or crotch but does not contain a knot and does not contain abrupt color variation. A blending burl is detectable at 1.8 m to 2.4 m (6 feet to 8 feet) as a swirl or roundel.
Cathedral - A grain appearance characterized by a series of stacked and inverted 'V" or cathedral type of springwood (earlywood) summerwood (latewood) patterns common in plain-sliced (fiat-cut) veneer (see split heart).
Centers - Inner plies whose grain direction runs -Id to that of the Outer plies. Included, as centers are parallel laminated plies.
Center Match - An even number of veneer components or leaves of equal size matched with a joint in the center of the panel to achieve horizontal symmetry.
Checks - Small slits running parallel to grain of wood, caused chiefly by strains produced in seasoning.
Comb Grain - A quality of rift cut veneer with exceptionally straight grain and closely spaced growth increments resembling the appearance of long strands of combed hair.
Core - The inner part of plywood between face and back, usually veneer. Sawn lumber, particleboard, MDF, hardboard, or other material is also used as cores.
Core, banded - Core that bas been made with banding on one or more-sides.
Crossbanding - Veneer used in the construction of plywood with five or more plies. Crossbands are placed as right angles to the grain of the faces and are typically placed adjacent to the face and back. Also refers to all inner layers of veneer whose grain direction runs perpendicular to that of the outer plies and includes parallel laminated plies.
Delaminatlon - Separation of plies or layers of wood or other material through failure of the adhesive bond.
Face - The better side of any plywood panel in which the outer plies are of different veneer grades. Also either side of a panel in which there is no difference in the veneer grade of the outer plies.
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.
Finger Joint - A series of fingers machined on the ends of two pieces of wood to be joined, which mesh together and ace held firmly in position with an adhesive.
Grain - The direction, size, arrangement and appearance of the fibers in wood or veneer.
Half-round - A method of veneer cutting similar to rotary cutting, except that the piece being cut is secured to a stay log," a device that permits the cutting of the log on a wider sweep than when mounted with its center secured in the lathe to produce rotary sliced veneer. A type of half-round cutting is used to achieve plain-sliced or fiat-cut veneer.
Hardboard - Homogeneous panels manufactured primarily from inter-felted lignocelluloses (wood) fibers consolidated under heat and pressure with a density of 497 kWm3 (31 lb/cu.ft.) or more.
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 nonactive or dormant Center of a tree generally distinguishable from the outer portion (sapwood) by its darker color.
Joint - The common edge between two adjacent materials in the same plane.
Knot - 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.
Knot, open - Opening produced when a portion of the wood substance of a knot has dropped out or where cross checks have occurred to produce an opening.
Knots, blending pin - Sound knots 6.4 mm (1/4 inch) or less that generally do not contain dark centers. Blending pin knots ace barely detectable at a distance of 1.8 m to 2.4 m (6 feet to 8 feet), do not detract from the overall appearance of the panel, and are not prohibited from appearing in all grades.
Knots, conspicuous pin - Sound knots 6.4 mm (1/4 inch) or less in diameter containing dark centers.
Knots, sound, tight - Knots that are solid across their face and fixed by growth to retain their place.
Knotholes - Openings produced when knots drop from the wood in which they were embedded.
Medium Density Fiberboard (MDF) - A panel or core product manufactured from wood fibers combined with a synthetic resin or other bonding system. MDF is manufactured with a 3 minimum density of 497 kg/m3 (31 lb/cu.ft.) up to 881 kg/m (55 lb/cu.ft.) by the application of beat and pressure by a process in which the fiber bond is substantially created by the added adhesive system.
Mineral Streaks - Natural discolorations of the wood substance caused by minerals deposited from water absorption.
Particleboard - A panel or core product composed of small particles of wood and wood fiber that are bonded together with synthetic resin adhesives in the presence of heat and pressure.
Plain-sliced (flat-cut) - Veneer sliced parallel to the pith of the log and approximately tangent to the growth rings to achieve flat-cut veneer. Plain-sliced veneer is cut using either a horizontal or vertical slicing machine or by the half-round method using a rotary lathe.
Pleasing Matched - A face containing components, which provides a pleasing overall appearance. The grain of the various components need not be matched at the joints. Sharp color contrasts at the joints of the components are not permitted.
Ply - A single sheet of veneer or several strips laid with adjoining edges that may or may not be glued, which forms one veneer lamina in a glued panel. In some constructions, a ply is used to refer to other wood components such as particleboard or MDF.
Plywood, Hardwood - A panel composed of an assembly of layers or plies of veneer or veneers in combination with lumber core, particleboard core, MDF core, hardboard core, or of special core material joined with an adhesive. Except for special constructions, the grain of alternate plies is at right angles and the face veneer is a hardwood species.
Quarter-sliced (Quarter-cut) - A straight grain appearance achieved through the process of quarter-slicing or through the use of veneer cut in any fashion that produces a straight grain effect. Cut is radial to the pith to the extent that ray fleck is produced, and the amount of fleck is not limited.
Ray Fleck - Portion of a ray as it appears on the quartered or rift-cut surface. Fleck is often a dominant appearance feature in Oak.
Rift-cut - A straight grain appearance achieved through the process of cutting at a slight angle to the radial on the half-round stay log or through the use of veneer cut in any fashion that produces a straight grain with minimal ray fleck.
Rotary-cut - Veneer produced by centering the log in lathe and turning it against a broad cutting knife which is set into the log at a slight angle.
Sapwood - The living wood of lighter color occurring in the outer portion of a tree, sometimes referred to as sap.
Sliced - Veneer produced by thrusting a log or sawed flitch into a slicing machine, which shears off the veneer in sheets.
Slip Matched - A sheet from a flitch is slid across the sheet beneath and, without turning, spliced at the joints.
Softwood - General term used to describe lumber or veneer produced from needle and/or cone bearing trees (see hardwood).
Solid Core - Plywood panels in which all inner plies are grade J or better. Splits up to 3.2 mm (1/8 inch) are allowed.
Split Heart - A method of achieving an inverted "V" or cathedral type of springwood (earlywood)/summerwood (latewood), plain-sliced (flat-cut) figure by joining two face components of similar color and grain. A cathedral type figure must be achieved by a single component in "AA" grade; the split heart method is allowed in grades "A" through "E". Each half of a split heart shall be subject to the minimum component width requirements for grade "A" and "B" faces.
Veneer - A thin sheet of wood, rotary cut, sliced, or sawed from a log, bolt, or flitch.
Wormholes - Holes resulting from infestation of worms.