The veneer sheet on the underside of a plywood panel, corresponding in thickness, and often in species, to the face veneer on the upper or exposed surface. Its grain runs parallel to the grain of the core, and crosswise to the grain of the cross-banding.
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.
Produced by an uneven contour of the annual rings. The veneer has the effect of being blistered. Must be cut rotary or half-round.
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 of 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.
A modification of ribbon stripe, the markings tapering out and producing a broken ribbon. If the log described in ribbon stripe also has a twist in the grain, the stripes are short or broken.
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 veneers leaf sizes are generally small and additionally are defective. While producing beautiful patterns, Burl veneer is difficult to work with.
Achieved when veneers are matched as described for book matching but the ends of the sheets are alsop 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.
A grain appearance characterized by a series of stacked “V” and inverted “V”. Pattern common in plain-sliced (flat-cut) veneer.
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 is always even, but the widths are not necessarily the same.
Small slits running parallel to the grain of wood, caused chiefly by strains produced in seasoning.
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.
Separation of the wood cells across the grain. Such breaks may be due to internal strains resulting from unequal longitudinal shrinkage or to external forces.
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.
Type of figure or irregularity of grain resembling a dip in the grain running at right angles, or nearly so, to the width of the 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 figure. Often resembling 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.
Found mostly in Maple or Birch, and is due to the fibers being distorted and producing a wavy or curly effect in the veneer.
A raised or hollowed cross grain cut caused genreally by a nick in the knife.
Checks, splits, open joints, knotholes, cracks, loose knots, wormholes, gaps, voids, or other openings interrupting the smooth continuity of the wood surface.
This is generally done with a straight grain veneer. If a rectangle is divided into 4 quadrants the veneers match at an angle to the quadrant line, and the grain forms a “V” at these lines. The result is a diamond shape formed by the grain directions.
Stains in wood substances. Common veneer stains are sap stains, end stains, blue stains, stain produced by chemical action caused by the iron in the cutting knife coming in contact with the tannic acid of the wood, and those resulting from the chemical action of the glue.
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.
A fine, strong, even, ripple figure as frequently seen on the backs of violins. It is found principally in Mahagony and Maple, but occurs sometimes in other woods.
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 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 next to the radial, it is close to parallel with the medullary ray and therefore develops the “Flake” effect.
Also called Plain Slicing, 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.
a) A section of a log made ready for cutting into veneers.
b) After cutting, all bundles are laid together in sequence as they were sliced.
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, Mahogany, etc.) and coarse grained (Oak, etc.). Coarser grained woods can usually be cut to develop a more conspicuous pattern.
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 leave can be kept in sequence. Half round cutting may be used to achieve “flat cut” veneer appearance.
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.
The nonactive center of a tree generally distinguishable from the outer portion (sapwood) by its darker color.
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 resulting from infestion of worms.
The line between the edges or ends of two adjacent sheets of veneer or strips of lumber in the same plane.
KNOTS, INCONSPICUOUS PIN
Sound knots 1/4 inch or less that do not contain dark centers. Inconspicuous or bending pin knots are barely detectable at a distance of 6′ to 8′, do not seriously detract from teh overall appearance of the panel, and are permitted in all grades.
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, TIGHT
Knots that are solid across their face and fixed by growth to retain their place.
The process of gluing or bonding the component sections of the plywood into a single permanent unit stronger than the original wood itself.
The trunk of the tree is the part that begins just above the stump and continues to just below the crotch, most veneers are cut from longwood by quarter, rotary, or flat cutting.
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.
MATCHING OF BURLS, CROTCHES, STUMPS
Because of their generally exotic grains, these wood figures need special treatment when being matched into faces. Burls and crotches in particular have a tendency to be buckled. In the process of making a panel face, the veneer needs to be flattened and patched if needed. They also have a tendency to develop fine hairline splits, so must be carefully handled in further manufacturing. This extra labor and care adds to the expense of using these grains, but the results are usually well worth the cost.
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.
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.
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.
A single sheet of veneer, or several pieces laid with adjoining edges, which form one layer in a piece of plywood.
A panel composed of an assembly of layers or plies or veneer (or veneers in combination with lumber-core, particleboard-core, MD-core, hardboard-core, or of special core material) joined with an adhesive. Except for special constructions, the grain of alternate plies is always approximately at right angles, and the face veneer is usually a hardwood species.
This cut requires the largest diameter logs and produces straight grained veneers. The quarter slicing of oak can result in the appearance of flake.
(Mismatched) A panel having the face made up of specially selected dissimilar (in color and grain) veneer strips of the same species and generally V-grooved at the joints between stripes to simulate lumber planking.
This is commonly done with a straight grain veneer, a rectangle is again divided into 4 quadrants. The grain direction is from the center point to the outside edge in each quadrant. The resulting appearance is that of a series of “Vs” formed by the grain match at the joint line pointed in at the center point.
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.
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.
If the twist in the grain of broken stripe is all in one direction a rope figure results.
The log is turned in a circular motion against a knife peeling off a continuous thin sheet of wood veneer (like unrolling wrapping paper), 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.
Irregular shaped areas of generally uneven corrugation on the surface of veneer, differing from the surrounding smooth veneer and occurring as the veneer is cut by the lathe or slicer.
The panel face is made from components running through the flitch consecutively. Any portion of a component left over from a face is used as the beginning component or leaf in starting the next panel.
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.
Veneer produced by thrusting a log or sawn flitch into a slicing machine which shears off the veneer in sheets.
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 perfected straight. Sometimes a grain pattern “runs off” the edge of the leaf, a series of leaves with the condition could usually make a panel – “look like it is leaning”. In book matching the pairs balance each other.
General term used to describe lumber or veneer produced from needle and/or cone bearing trees. (See Hardwood).
A distinct kind of wood.
SPLICED FACE VENEERS
Face veneers that have been joined together in any one of several matching effects through the careful factory process of tapeless splicing.
Separations of wood fiber running parallel to the grain.
Natural discolorations of the wood substance.
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.
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).
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 substraights to form a panel.