 Knot
(Pin): Sound
knots less than 1/4" in diameter. (See image
of Pin Knot at right.) Knot (Sound): Knots that are solidly fixed by growth and retain their place in lumber or veneer. Knothole: Opening produced when knots drop from the wood in which they were once embedded. Lap: The overlapping of one piece of veneer on another in the same layer of ply.
Patches: Filler material inserted into defects of veneers or panels for repair. Plain Sliced: Veneer sliced from a log tangent to the tree's annual rings. Ply: A single sheet of veneer forming one layer in a multi-layered piece of plywood. Plywood, Hardwood: A panel composed of layers of inner plies, or other core material joined with an adhesive to a face veneer of hardwood and a back veneer, usually also composed of hardwood. Quarter Slicing: Quartered log sliced at right angles to the growth rings. Rift Cut: Veneer cut from a quartered log on a 90 degree angle to the grain. Rotary Cut: Veneer peeled from a whole log set in a lathe and turned against a special knife
Slip Matched: Veneer sheets that are laid side by side to form a whole sheet with a repetitive grain appearance.
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Medium
Density Fiberboard (MDF): A panel or core material manufactured
from pressure cooked wood fiber, resin and wax. (See
MDF image at right.)
Mineral
Streak: A discoloration of hardwood and hardwood veneer.
(See image of mineral streak at left.)
Particleboard:
A panel or core material manufactured from pressed sawmill
shavings, resin and wax. (See image at
right.)
Sapwood:
The light colored, living portion of a tree located between
the heartwood and the bark. (See
image of sap in oak at left.)
 Backs:
The
reverse side to the face of a plywood panel. Generally, the poorer
side of any grade plywood panel calling for a face and a back. (Image
shows "2" or "Medallion" Back.)
Bark Pocket: A small area of bark around which normal wood has grown.
Crossbar: An imperfection or irregularity in the grain of wood running at right angles to the length of the board. Cross banding: Inner ply veneer placed at right angles to the core, face and back of a plywood panel. Defects: Anything interrupting the smooth flow of a wood surface. This includes loose knots, splits, voids, wormholes, bark pockets and others. Delamination: The separation of the inner plies in a panel due to the failure of the adhesive bond. Face: The best side of a plywood panel in which the outer veneers are of different grades.
Half-Round Slicing: Off-center slicing cut slightly across the annular grown rings resulting in half-round, plain sliced or rotary characteristics. Hardwood: General term referring to the wood of many different deciduous trees as opposed to the softwood of evergreen or coniferous trees. Does not relate to the density of the wood.
Knot (Open): Opening produced when a portion of a know has dropped out or separated due to seasoning. |
Burl:
A swirl or twist in the grain of wood, usually occurring
near a knot, but which itself does not contain a knot.
(See image of burl at left.)
Core:
The innermost portion of plywood usually composed of veneer.
Also referred to as a "center." A core may also be made
of fiberboard, particleboard or lumber. (See
image of lumber core at right.)
Gum
Spots: Accumulation of resinous material often found on
panel surfaces. May be removed by sanding. (See
image of gum spots at right.)
Knot:
Circular portion of a board or veneer that was once the
base of a branch or twig growing from the trunk of a tree.
(See image of half-inch knot at left.)