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Wood Veneer Glossary

10 Mil Veneer

 

A veneer face of any species applied to a 10 mil paper back. Although face thickness may vary, the paper back thickness is consistent.

20 Mil Veneer

 

A veneer face of any species applied to a two-ply paper back with resin between the layers,making for a 20- to 22-mil paper back. Face thickness may vary but the paper back thickness is consistent.

2 Ply Veneer

 

A decorative wood veneer face with a utility grade wood backer applied at an opposing direction to the face veneer. Also referred to as wood on wood.

Acclimation

 

The process of allowing the veneer (and often the substrate) to adapt to environmental conditions such as temperature and relative humidity. Veneer and substrate should be acclimated together (under the same conditions) for a period of at least 48 hours before applying the veneer.

Bird's Eye

 

Due to local sharp depressions in the annual rings, accompanied by considerable fiber distortions. Once 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 bird's eyes. It occurs only in a small percentage of Maple trees.

Bee's Wing

 

Small and tight mottled figure similar in appearance to a bee's wing. Occurs mostly in East Indian Satinwood, also occasionally in eucalyptus and mahogany veneer .

Blister

 

Produced by an uneven contour of the annual rings. The veneer has the effect of being blistered. Must be cut rotary or half-round.

Block Mottle

 

An irregular variation in the cellular structure of the wood which shows as blocky patches across the grain of the veneer. It is commonly found in makore and anigre.

Book Matching

 

Achieved when successive veneer leaves in a flitch are turned over like the pages in a book and are glued in this manner. Since the reverse side of one leaf is a mirror image of the succeeding leaf, the result is a series pairs. Individual panels can be matched this way or you can achieve this look over many panels by sequence-matching the panels. Book matching is the most common match. A common problem in book matching is when the "tight" and "loose" sides are matched and reflect light and stains differently. This may yield color variations in some species which may be minimized by proper finishing techniques.

Bubble

 

A raised area caused by improper gluing technique or faulty adhesion. Bubbling can be inspected with a light, and often rectified with a razor and .

Bubble Free Veneer

 

A veneer face of any species applied to a double paper layer of two 10 mil papers. With moisture resistant thermoset glue, the overall backer thickness is 22 mils.

Burl Veneer

 

Produced from a large, wartlike growth on the trunk of the tree. The grain pattern typically resembles a series of eyes laid side by side. Obviously the veneer’s leaf sizes are generally small and additionally are defective. While producing beautiful patterns, burl veneer is difficult to work with. Burl wood is commonly produced from maple and walnut veneer, but can be produced from other species as well. Burl veneer sheets tend to be smaller than other sheets.

Butt Matching

 

Achieved when veneers are matched as described for book matching but the ends of the sheets are also matched. At times, the veneer being used is not long enough to cover the desired panel heights. In this case the veneer leaves can also be flipped end for end and the ends matched.

Button Figure

 

Wood species with large medullary rays are quarter cut to reveal the harder and shiny rays which show up as flakes or buttons on the straight grained background.Species such as white oak, lacewood and American sycamore are cut this way specifically to reveal this figure.

Cathedral

 

A grain appearance characterized by a series of stacked "V" and inverted "V". Pattern common in plain-sliced (flat-cut) veneer.

Center Matching

 

Each panel face is made with an even number of flitch sheets with a center line appearing at the midpoint of the panel and an equal number of veneer sheets on each side of the center line. The number of leaves on the face are always even, but the widths are not necessarily the same.

Chatter Market

 

An imperfection that results in uneven veneer thickness as a result of vibration in the veneer slicing machine.

Checks

 

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

Clear

 

Clear lumber or veneer is free of blemishes or defects, making it a select grade of wood.

Cold Creep Comb (Grain)

 

Undesirable movement of veneer along or away from the substrate due to changes in seasonal temperature or humidity.

A high-quality rift cut with very straight, very tight grain orientation.

Core

 

There are four types of core construction used in plywood panels: a) Lumber Core: Consists of a heavy core of sawn lumber between crossbands. The thick center core permits doweling, splining and dovetailing. b). Veneer Core: Method of plywood construction consisting of 3,5,7 or more plies of veneer laid with grain direction of adjacent plies at right angles to each other. c). Particle Board: This type of core consists of chips or flakes of resin-coated wood fused together under heat and pressure to form a core for plywood. d). Mineral Core: Used for fireproof panel construction. Veneers are bonded to a hard noncombustible material.

Cross Fire

 

Figures which extend across the grain as mottle, fiddle-back, raindrop and finger-roll are often called cross figure or cross fire. A pronounced cross fire adds greatly to the beauty of the veneer.

Crossband

 

The veneer sheet between the core and face veneer. Its grain runs at right angles to the grain of adjacent layers, thereby providing the remarkable stability of hardwood plywood.

Crossbar

 

Type of figure or irregularity of grain resembling a dip in the grain running at tight angles, or nearly so, to the width of the veneer.

Crotch Veneer

 

Produced from the portion of the tree just below the point where it forks into two limbs. The grain is twisted, creating a variety of flame figures. Often resembles a well formed feather. The outside of the block produces a swirl figure that changes to full crotch flame figure as the cutting approaches the center of the block.

Crown Cut

 

See Flat Cut (below)

Curly Figure

 

Found mostly in Maple or Birch, and is due to the fibers being distorted and producing a wavy or curly effect in the veneer.

Delamination

 

Delamination describes the process by which the veneer separates from its backing, or when the entire veneer sheet separates from the substrate after application. Delamination often occurs due to improper adhesive application, such as when the substrate absorbs too much adhesive or when the adhesive has not been properly mixed or dried between application processes..

Domestic 
Wood Veneer

 

A reference to wood veneers commonly found in the United States and North America as a whole.

Edgeband

 

Thin strips of veneer used to cover the exposed edges of panel substrates. This veneer is usually available in rolls of various length and comes either pre-glued or unglued.

Exotic 
Wood Veneer

 

A common reference to wood veneers not indigenous to or grown in North America. Some burls and figured woods might also fall into this category.

Face

 

The better side of any plywood panel in which the outer plies are of different veneer grades. Also veneer spliced to a certain pattern and cut to exact size.

Fiddle Back

 

A fine, strong, even, ripple figure as frequently seen on the backs of violins. It is found principally in Mahogany and Maple; cut occurs sometimes in other woods.

Figure

 

The pattern produced in a wood surface by annual growth rings, rays, knots, deviations from natural grain such as interlocked and wavy grain, and irregular coloration. Appears across the grain. Mottle, fiddleback and raindrop are often called cross figure or cross fire.

Flake
Fleck Figure

 

Flake figure is developed only in those species which have very heavy medullary ray growth, specifically Oak, Lacewood, and Sycamore. When the saw or knife cut is directly on or near to the radial, it is close to parallel with the medullary ray and therefore develops the "Flake" effect. This is also known as Fleck figure.

Flash Time

 

The amount of time you need to wait after applying glue to the substrate and before you can apply the veneer.

Flat Cut

 

Also called Plain Slicing, it is the most common method of veneer manufacturing, producing a grain pattern known as cathedral. Because each leaf in the flitch is similar, a consistent and even matching pattern is possible. Flat cut veneer is ideally suited for wall panels and furniture.

Flexible Veneer

 

Wood veneer which is joined, processed, sanded and backed with paper or other material to create a fully ready to use dimensional sheet of real wood veneer.

Flitch

 

A Section of a log made ready for cutting into veneers.
After cutting, all bundles are laid together in sequence as they were sliced.

Grading

 

Classifying veneers according to quality standards for each species. This greatly impacts the price and end use of the veneer.

Grain

 

Size and arrangement of the cells and pores of the living tree. Grain is not synonymous with figure. Woods fall into three groups: Fine grained (Birch, Cherry, Maple, etc.), medium grained (Walnut veneer, Mahogany, etc.) and coarse grained (Oak, etc.).) Coarser grained woods can usually be cut to develop a more conspicuous pattern.

Gum

 

Patches or black spots occurring primarily in American Cherry. This undesirable characteristic is acceptable in varying degree in most grades of Cherry.

Half Round
Slicing

 

Similar to rotary peeling, also producing a high veneer yield. Used primarily to add width to narrow stocks by increasing the plane of cut. Also used to enhance a particularly wild grain pattern. Matching is possible because the leaves can be kept in sequence. Half round cutting may be used to achieve "flat cut" veneer appearance.

Hardwood

 

General term used to designate lumber or veneer produced from broad-leafed or deciduous trees in contrast to softwood, which is produced from evergreens or coniferous trees.

Heartwood

 

The non-active center of a tree generally distinguishable from the outer portion (sapwood) by its darker color.

Herringbone

 

Veneer strips are used and matched to both sides of the center line, at an angle. The resulting appearance is reminiscent of the bones of a fish as they are attached to the back bone.

Holes, Worm

 

Holes resulting from infestation of worms.

Joint

 

The line between the edges or ends of two adjacent sheets of veneer or strips of lumber in the same plane.

Knots, Pin

 

Sound knots 1/4 inch or less that do not contain dark centers. Inconspicuous or blending pin knots are barely detectable at a distance of 6' to 8', do not seriously detract from the overall appearance of the panel, and are permitted in all grades.

Knots, 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
Sound or Tight

 

Knots that are solid across their face and fixed by growth to retain their place.

Lamination

 

The process of gluing or bonding the component sections of the plywood into a single permanent until stronger than the original wood itself.

Lap

 

A defect in which a piece of veneer overlaps the adjacent piece.

Leaf

 

A single veneer strip or piece from a bundle. May also be referred to as a panel.

Looseside

 

In knife-cut veneer, that side of the sheet that was in contact with the knife as the sheet was being cut. The bending of the wood at the knife edge causes cutting checks.

Marquetry

 

Inlaid work produced by joining small pieces of veneer, often of contrasting species like maple and walnut veneer, to produce unique geometric patterns. (Marquetry = pictures; Parquetry = patterns.)

Medium Density Fiberboard (MDF)

 

A panel or substrate material manufactured from wood fiber and resin. Generally considered the best substrate for laminating veneers.

Medullary Rays

 

Figures that run parallel to the growth rings in certain species such as white oak, which appear as ribbons or streaks. See: Flake Figure, which is produced by the presence of medullary rays.

Mineral Streak

 

A dark patch or discoloration in the wood which occurs because of the presence of minerals in the soil in which the tree is growing.

Mottle Figure

 

A variegated pattern which consists principally of irregular, wavy fibers extending for short distances across the face. If there is also some irregular cross figure in a log with a twisted interwoven grain, the broken stripe figure becomes a mottle.

No Black Line, NBL

 

Same as Wood on Wood or 2-Ply Veneer.

Particleboard

 

A panel composed of small particles of wood and wood fiber that are bonded together with synthetic resin adhesives in the presence of heat and pressure.

Patches

 

Wood plugs or shims sometimes used to fill voids in wood veneer.

Peanut Shell Figure

 

A type of figure occurring in some woods similar to quilted or blistered figure. These woods are typically cut to promote a random and wild grain effect with a three dimensional feel. Occuring most commonly in Tamo Ash and Bubinga.

Pecky

 

Pockets of disintegrated wood caused by localized decay, or wood areas with abrupt color change related to localized injury such as bird peck. Peck is sometimes considered as a decorative effect such as bird peck in pecan and hickory or pecks in cypress.

Pepper

 

Thin black knots which are common in the figure of yew veneer.

Pitch Pocket

 

A small opening running parallel to the growth rings, caused by the presence of pitch (resin), common in pine and cherry veneer.

Pin Knot

 

See Knots, Pin

Phenolic Veneer

 

A flexible veneer face with a phenolic type backing material. Sometimes referred to as laminate veneer.

Plain Sliced

 

See Flat Cut.

Polyvinyl Acetate

 

Also known as PVA, this is a common type of wood glue sometimes referred to simply as "white glue."

Pommele Figure

 

Comes from the French word, "Pomme" (Pomme = Apple). The term given to a regular veneer marking which resembles apples.

Premium Grade

 

A common reference to AA Grade veneer when veneer grading standards are applicable.

PSA Veneer

 

Pressure Sensitive Adhesive, often referred to as peel and stick veneer. This is a self-adhesive veneer which doesn't require the application of glue on the back of the veneer sheet, saving several steps in veneer application.

Quarter Slicing
or Quarter Cut

 

This cut requires the largest diameter logs and produces straight grained veneers. The quarter slicing of oak can result in the appearance of flake.

Quilted Figure

 

A larger, more exaggerated version of pommele or blister figure. The cellular figure is elongated and closely crowded giving it a pillowy three dimensional effect. It is most commonly found in Maple, Mahogany, Moabi and Sapele.

Random Matched
/ Planked

 

A panel having the face made up of specially selected dissimilar (in color and grain) veneer strips of the same species to stimulate lumber planking.

Raw Veneer

 

Wood veneer cut from any log by any slicing method that is dried and then used as a natural flitch or leaf of veneer. Much production and machining of this veneer has to be accomplished prior to the final application to a substrate.

Reconstituted Veneer

 

A man-made veneer which uses real wood fiber with natural colorants to simulate various color, figure and grain seen in real wood veneers.

Reverse Slip Matching

 

Matching in which the veneer panels are slipped out from under each other, with every other panel flipped end-to-end, balancing the appearance.

Ribbon Stripe

 

Result of quarter-slicing a log and the appearance actually is between broken stripe and plain stripe. It gives the general appearance of a ribbon sometimes slightly twisted.

Rift Cut

 

Produced by cutting at a slight angle to the radial to produce a quartered appearance without excessive ray flake. The rift cut method, commonly used for Oak, can only be used on sizable logs. Rift cut veneer can easily be sequenced and matched.

Ropey Figure

 

If the twist in the grain of broken stripe is all in one direction, a rope figure results.

Rotary Slicing

 

The log is turned in a circular motion against a knife, peeling off a continuous thin sheet of wood veneer (like unrolling wrapping paper). It is the most economical method of producing veneer, resulting in the highest yield. The grain is inconsistent and leaves are most difficult to match. This type of veneer is best suited for paint grade or utility surfaces.

Running Match

 

The panel face is made from components running through the flitch consecutively. Any portion of a component or leaf in starting the next panel.

Sand-Through

 

An undesirable condition caused by sanding too deeply, often penetrating the veneer face and exposing the glue line. Sand through is irreversible and ruins the panel.

Sapwood

 

This is the outer portion of the tree. As additional layers of growth accumulate on the outer perimeter, the inner layers of the sapwood becomes heartwood. Sap is lighter in color and the differentiation in color and thickness of the sap layer varies considerably by species.

Select Grade

 

A common reference to A Grade veneers when veneer grading standards are applicable.

Sequence Matching

 

A method of arranging veneer faces such that each face is in order relative to its original position in the tree and, therefore, contains features of grain and figures similar to adjacent faces.

Set Time

 

The amount of time the veneer panel will need to be pressed or clamped in order to ensure proper adhesion to the substrate.

Shakes

 

Similar to checks, shakes are small cracks in veneer that follow the growth rings. Typically the presence of shakes renders a log unsuitable for use as veneer.

Sheet Veneer

 

Same as Flexible Veneer.

Sketch Face

 

A method of joining individual leaves of veneer together to create a single, standard dimensional sheet veneer. This method uses a combination of book matching and butt matching and is commonly used with burl and crotch veneers.

Sliced

 

Veneer produced by thrusting a log or sawn flitch into a slicing machine which shears off the veneer in sheets.

Slip Matching

 

Means that veneer leaves in a flitch are "slipped." Successive veneer leaves in a flitch are "slipped" one alongside the other and edge-glued in this manner. The result is a series of grain repeats, but no pairs. The danger with this method derives from the fact that grain patterns are rarely perfectly straight. Sometimes a grain pattern "runs off" the edge of the leaf. A series of leaves with this condition could usually make a panel look like it is leaning. In the book matching the pairs balance each other.

Softwood

 

General term used to describe lumber or veneer produced from needle and/or cone-bearing trees. (See Hardwood).

Spalting

 

A pattern of dark lines in wood caused by fungal infection. This is often an aesthetically desirable feature.

Spliced Face Veneer

 

Face veneers that have been joined in any one of several matching effects through the careful factory process of tapeless splicing.

Spruce-Pine-Fir (SPF)

 

Three common softwood species grouped together for ease of production and marketing of lumber. They are affordable and easily worked.

Stain

 

Discoloration to the veneer face that occurs from excessive exposure to the sun, or to excessively dry conditions.

Steaming

 

The process of heating logs in hot water before slicing veneer from them. This makes the logs more pliable and creates a signature pinkish color, or "cast."

Streaks, Mineral

 

Natural discolorations of the wood substance.

Stump Veneer

 

Produced from the base of the tree. Here the grain pattern is always swirly twisted and often accompanied by cross fire and patches of burl. The sizes are normally small.

Substrate

 

The material used as the surface to which the veneer is applied. Choice substrates are MDF, particleboard and plywood.

Tear Out

 

An area where wood fibers have torn or separated during slicing. Tear-out can also occur along the edges of a veneer sheet during trimming.

Tiger

 

A figure common in maple veneer, in which a series of flakes or stripes run parallel to the grain. Sometimes also known as curly, fiddleback or flame.

Swirl Grain

 

A lesser degree of crotch figure. The grain tends to swirl around in a random pattern. This figure frequently appears in cherry, mahogany, walnut and maple.

Tight Side

 

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

Veneer

 

A thin sheet of wood, rotary cut, sliced or sawn from a log or flitch. Veneering goes back to the early days of the Egyptians, about 3,500 years ago. Down through the years and cultures, veneering has enriched furniture and architectural interiors with sheets of rare and beautiful woods bonded to other plain, sturdy wood based substrates to form a panel.

Veneer Face

 

See description for Spliced Veneer Face (above).

Veneer Log

 

Logs, either hardwood or softwood, which have specific characteristics or traits which qualify them to be sliced for veneer only. Less than 5% of all logs are of veneer quality.

Wood on Wood Veneer

 

Same as 2-Ply Veneer and commonly interpreted as no black line veneer.