Hardwood Plywood Terms

Glossary

Backs

Some plywood panels are specified with different grades of veneer on each side. The lower grade side of a plywood panel is called the Back.

Bark Pocket

An area on a sheet of veneer where a tree branch grew, thus trapping a small amount of bark, usually around a knot.

Core

Inner plies of a panel product, usually composed of veneer. Alternatively, cores can be made of particleboard, MDF or lumber.

Crossbar

A defect in panel manufacturing where a piece of veneer runs perpendicular to the length of the board.

Crossbanding

Crossbanding refers to the orientation of successive layers of veneer layup by placing them perpendicular to the face and back of a plywood panel.

Defects

Any number of imperfections in a panel product’s appearance or surface, including splits, stains, voids, holes, open knots, bark pockets and other issues.

Delamination

Panel separation caused by adhesive failure.

Face

Some plywood panels are specified with different grades of veneer on each side. The higher-grade side of a plywood panel is called the Front.

Flitch

The complete bundle of thin sheets of veneer after cutting, laid together in sequence as they were sliced or sawn.

Grain

The distinctive, natural pattern, size and direction of the fibers in sliced or sawn wood.

Gum Spots

Sap or resin left on wood from veneer sawing or slicing. Gum spots can usually be removed by sanding.

Half-Round Slicing

When a log is cut tangential to its growth rings, the result is a plain sliced or rotary grain pattern.

Hardwood

 Any species of deciduous tree lumber or veneer. Coniferous tree lumber is called Softwood. The term Hardwood has no relationship to the density of the wood.

Heartwood

The oldest part of a log radiating from the center, consisting of mature wood that has stopped growing. Usually, heartwood is darker than sapwood.

Knot

The place on lumber or veneer where a branch once emerged from the trunk of the tree.

Knot (Open)

The condition of a knot that has separated from the fibers surrounding it due to the drying process.

Knot (Pin)

Very small knots less than 1/4″ in diameter.

Knot (Sound)

Knots that have not separated from the surrounding fiber during the drying process.

Knothole

A void in lumber or veneer created when a knot is missing from its original location.

Lap

Orientation of two pieces of veneer next to one another in the same layer of ply.

Medium Density Fiberboard (MDF)

A wood flour material made from pressure-cooked wood fiber, resin and wax.

Mineral Streak

A discoloration of hardwood and hardwood veneer

Particleboard

A panel or core material manufactured from pressed sawmill shavings, resin and wax.

Patches

Material placed onto defects in veneers to repair voids and other imperfections

Plain Sliced

When a log is cut tangential to the tree’s annual growth rings

Ply

One layer in a wood panel product. Varying numbers of plies make up a sheet of plywood.

Plywood, Hardwood

A panel product with a hardwood face veneer. The back veneer is usually hardwood as well. Hardwood plywood may or may not have softwood inner plies.

Quarter Slicing

A veneer cutting method in which a log is sliced at right angles to the annular growth rings

Rift Cut

A veneer cutting method in which a log is cut into quarters and then at a 90-degree angle to the grain direction.

Rotary Cut

A peeling process whereby a whole log is set in a lathe and turned against a large knife.

Sapwood

The youngest, newest wood in a lumber or veneer, located between the heartwood and the bark.

Slip Matched

When veneer is carefully aligned to form a whole sheet with a pleasing grain appearance.

Splits

Cracks in the wood fiber running parallel to the grain in veneer, usually from drying.

Veneer

Peeled or sliced sheets of thin wood used to make the layers of plywood.