Wood


A

Appleply

A trade name of States Industries for a proprietary plywood panel product composed of a core of 1/16" Western Red Alder veneers most commonly available with face veneers of Maple or Birch. However, any face or back veneer is available, too. Noted for the attractive decorative appearance of the edge of a panel.

Armorcore

See Composite Core.

 
B

Backer

A non-decorative laminate used on the back of composite panel constructions to protect the substrate from changes in humidity and to balance the panel construction.

Backs

The reverse side to the face of a plywood panel. Generally the poorer side of any grade plywood panel which has a face and a back.

 

Balanced Construction

A panel construction that will not warp when subjected to uniformly distributed moisture changes.

Balanced Match

Two or more veneer components or leaves of equal size to make up a single face.

 

Birdseye

Due to local sharp depressions in the annual rings, accompanied by considerable fiber distortions. One the depressions are formed succeeding growth rings follow the same contour for many years. Rotary veneer cuts the depressions crosswise, and shows a series of circlets called birdseyes. It occurs in only a small percentage of maple trees.

 

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.

 

Bow

The deviation from absolute flatness along the length of the panel.

Burl

A swirl or twist in the grain of wood, usually occurring near a knot but which does not itself contain a knot.

C

Cathedral

A grain appearance characterized by a series of stacked or inverted "V" or cathedral type of springwood (earlywood) summerwood (latewood) patterns common in plain sliced (flat cut) veneer.

Centermatch

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.

 

Chatter

A wavy condition across the width of a panel caused by sanding. These marking are parallel to one another between 3 and 2 inch apart and perpendicular to the sander grit markings. Sometimes they can be felt but always can be seen.

Checks

Small slits running parallel to the grain of wood caused by strains produced in seasoning.

 

Classic Core

See Composite Core.

 

Clear face cutting

A cutting having one clear face (ordinary season checks are admitted) and the reverse side sound as defined in Sound Cutting. The clear face of the cutting shall be on the poor side of the board, except when otherwise specified.

 

Comb Grain

A quality of rift cut veneer with exceptionally straight grain and closely spaced growth increments.

Composite Core

Any one of a number of different core configurations produced from various combinations of wood veneers and reconstituted or engineered wood fiber materials such as MDF, particleboard and hardboard. This type of core configuration generally provides the advantages of the flatness of the reconstituted wood fiber crossband with the lightness of traditional veneer core.

Core

The innermost portion of plywood usually composed of veneer. Also referred to a "center." A core may also be made of fiberboard or, particleboard or lumber.

 

Crossband

Inner ply veneer placed at right angles to the core, face and back of a plywood panel.

 

Cup

Deviation from a straight line stretched across the width of a panel or board.

Curly

Curly figure is found mostly in maple or birch and is due to the fibers being distorted and producing a wavy or curly effect in the veneer.

D

Delamination

The separation of the panel's face layer from the core, or a laminate from a substrate or separation of the inner plys usually from failure of the adhesive bond.

Density

The weight of a panel as measured in pounds per cubic foot.

 

Doze (also Dote)

A form of incipient decay characterized by a dull or lifeless appearance of the wood and accompanied by a loss of strength and softening of the wood substance.

 
E

End Matched

Often called butt matched, the veneers are matched as described for book matched, but the ends of the sheets are matched. Quite often, veneers are both book matched and end matched which is called a four way match.

F

Face

The best side of a plywood panel in which the outer veneers are of different grades.

Fiberboard

See MDF - Medium Density Fiberboard.

 

Fiber Raise

Face fibers that are raised above the surrounding surface causing a rough surface. Usually caused by excessive absorption of moisture.

Fibers

The slender threadlike elements or groups of wood fibers resulting from chemical or mechanical defiberization, or both, and sometimes referred to as fiber bundles.

 

Fiddle

Back-A fine, strong, even, ripple figure as frequently seen on the backs of violins. It is found principally in mahogany and maple, but occurs sometimes in other woods.

 

Fines

Small moist almost dust-like wood particles found on the surface of the reconstituted wood panel. The presence of fines helps create a smooth, tight surface.

 

Finger Joint

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.

Flake, Ray

A portion of a ray as it appears on the quartered surface. Flake can be a dominant appearance feature in oak and is sometimes referred to as fleck.

Flat-Cut

See Plain-Sliced.

 

Fleck

See Flake.

 

Flitch

A complete bundle of thin veneer sheets laid together in sequence as they are cut from a given log or section of a log.

G

Gap

Open slits in the inner plys or improperly joined veneers.

Gum Pockets

Well defined openings between the rings of annual growth containing gum or evidence of prior gum accumulation.

 
H

Hardboard

A high quality panel manufactured from specially engineered fibers which are compressed under heat and pressure. The panels, which are produced by a wet process, can have one smooth side and a screen back (smooth one side or S1S) or be smooth on both sides (S2S). Pegboard is commonly manufactured from hardboard.

Hardwood Plywood

Composed mostly of inner plys peeled from fir, poplar, lauan or other species of either soft or hardwood, only the face and back panels are pure hardwood veneers of 1/30th to 1/40th or less of an inch thick.

 

Hardwood

General term referring to the wood of many different deciduous trees as opposed to the softwood of evergreen or coniferous. Does not relate to the density of wood.

Heartwood

The center portion of a tree consisting of mature wood that has stopped growing. Generally distinguishable from sapwood or the growing outer portion by its dark color.

High Pressure Laminate

A sheet material formed from multiple layers of kraft paper saturated with phenolic resin; a decorative layer of paper saturated with melamine resin; and a very thin top sheet of paper heavily saturated with a melamine resin. Fused together in a hot press under high temperature and pressure to produce a stiff plastic sheet.

 

Holes, Worm

Resulting from an infestation of worms.

 
K

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.

Knot (Sound)

Knots that are solidly fixed by growth and retain their place in lumber or veneer.

 

Knot (Pin)

Sound knots less than 3" in diameter.

 

Knot (Open)

Opening produced when a portion of a knot has dropped out or separated due to seasoning.

 
L

Loose Side

In knife-cut veneer, that side of the sheet that was in contact with the knife as the veneer was being cut, and containing cutting checks (lathe checks) because of the bending of the wood at the knife's edge.

LPL

Low pressure laminate. A preprinted or solid color decorative paper that has been saturated with resin. Under heat and pressure, it bonds to a board surface without need for additional adhesive.

 
M

MDF - Medium Density Fiberboard

A material consisting of a wood fiber - resin combination formed into a homogenous mat of random fiber orientation, then hot pressed and finished. It can be machined or sanded to a smooth finish.

Melamine

A laminate that derives its name from the melamine resin system used to saturate the paper laminate and adhere it to the substrate. It is the resin that gives durability and toughness to high-pressure plastic laminate and melamine panels. Also a generic term for panels surfaced with melamine papers.

 

Mill Run

A down graded product due to visual defects such as oil stains, resin spots or surface discoloration.

 

Mineral Streak

A discoloration of hardwood and hardwood veneer.

 
N

Natural Veneer

Composed of both heartwood and sapwood. Select or uniform heartwood veneers are usually more expensive than their sapwood counterparts since the heartwood is the smallest is the smallest portion of the tree. Natural veneers are a combination of both heartwood and sapwood and is therefore generally less expensive than Select or Uniform veneers.

O

Occasional

A small number of characteristics that are arranged somewhat diversely within the panel face.

P

Paint Grade Veneer

A lower grade panel, it has, however, a smooth enough finish so none of the grain pattern or natural characteristics of the wood show through when it is painted.

Particleboard

A panel product constructed from wood particles. The wood particles are blended with resin and wax and pressed into panels. It is firm and solid throughout and makes a good core for hardwood plywood, and, depending on the grade an excellent underlayment for wood veneers, high pressure laminate and other overlay materials.

 

Particles

The aggregate component of a particleboard manufactured by mechanical means form wood including all small subdivisions of wood such as flakes, shavings, slivers, and wafers. Particle size may be measured by screen mesh that permits passage of particles and another screen upon which they are retained, or by measured dimensions as for flakes.

 

PBU - Particleboard Underlayment

A particleboard product manufactured for interior use as the smooth surface layer under finish floor coverings in double layer floor construction.

 

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 can be cut using either a horizontal or vertical slicing machine or by the half-round method using a rotary lathe.

 
Q

Quarter Slicing

Quartered log sliced at right angles to the growth rings.

R

Ray Flake

See Flake.

Repairs

A patch, shim or filler material inserted and/or glued into veneer or a panel to achieve a sound surface.

 

Resin Spots

Hard pieces of dark or black foreign material in the face layer that are composed of glue and wood dust.

 

Ribbon Stripe

In some woods, principally mahogany, wide, unbroken stripes can be secured. It is produced by cutting on the quarter a log that shows growth rings.

 

Rift Cut

Veneer cut from a log sliced at right angles to the growth rings.

 
S

SL1E

Nomenclature used to describe a board with one edge that has been cut straight to facilitate further processing.

S2S

Shorthand for "Smooth 2 Sides." Used to describe material, usually a board, that has been planed smooth on both sides.

 

S1S

Shorthand for "Smooth 1 Side." Used to describe material, usually a board, that has been planed smooth on only one side. The other side is left rough.

 

Sand Through

A condition where the face layer has been sanded off exposing the core. These areas will appear to be darker and larger particles will be exposed.

 

Sapwood

The light colored, living portion of a tree located between the heartwood and the bark.

 

Select Veneer

Composed entirely of heartwood or sapwood and matched for both grain pattern and color.

 

Shop Grade

A down graded product due to visual defects (as in Mill Run), which can also have damaged corners, edges, face or back defects such as missing veneer or sanding dips. The panel must be 75% to 90% usable depending on the nature of the manufacturing.

 

Slip Matched

Veneer components are laid side by side to form a whole sheet with a repetitive grain appearance.

 

Smooth, Tight Cut

Veneer carefully cut to minimize lathe checks.

 

Splits

Separations of wood fiber running parallel to the grain.

 

Softwood

General term used to describe lumber or veneer produced from needle and/or cone bearing trees.

 

Solid Core

Plywood panels in which all inner plys are grade J or better. Splits up to 3.2 mm or 1/8th of an inch are permitted.

 

Species (Trees)

An internationally established botanical classification of trees.

 

Spliced Veneers

Spliced veneers are composed of several pieces of veneer varying in width that are glued together to form a whole sheet. The way they are laid out during composing determines the final look of the veneer.

 

Split

A lengthwise separation of the wood in a board or veneer due to the tearing of wood fiber parallel to the grain.

 

Stain

In hardwoods, the word "stain" is used to describe the iniitial evidences of decay.

 

Superply

See Composite Core.

 
T

Tight Side

In knife-cut veneer, that side of the sheet that was farthest from the knife as the sheet was being cut containing no cutting checks (lathe checks).

U

Unbalanced Construction

Warping caused when the individual layers or components of a panel do not respond equally to changes in moisture or humidity.

Uniform Veneer

Composed entirely of heartwood and sapwood but matched for color only.

 
V

Veneer

A thin sheet of wood, rotary cut, sliced or sawed from a log, bolt or flitch and used as interior ply or decorative face.

W

Wane

The presence of bark, or the lack of wood from any cause on the edge or corner of a piece of lumber.

Warp

When a board bends, twists or turns from a straight line due to unbalanced construction, excessive moisture pick up, wetting or other unfavorable exposure.

 

Whole Piece Veneers

Unspliced continuous pieces of veneer that have been peeled from a log using the rotary process.

 

Gunderlin © 2008