Blue stains on the surface of the veneer, which can be caused by inadequate removal of water (too low heating output at pressing bar, too fast slicing) during slicing, as water standing on the surface of the veneer reacts with the constituents as a result of oxidation.
Figure or pattern of veneers, made from burrs (see Chap. 2.3.4). Burrs grow above the ground (Oak, Ash, Elm) or as a root burr under the ground (Madrona, Myrtle, Vavona, Californian Walnut). Partially figured burrs and logs are called Half-Burr or Clusters.
"Figure" with uniform annual ring spacing and absolutely straight growth. A variation of crown (i.e. perfect arches). Sought after build up of the texture in Flamed figure packs. Is considered to be particularly elegant.
Abbreviation ρ, the mass of a unit volume of wood, expressed in g/cm³. The dry density is given for a specific wood moisture content. Most wood properties depend on the dry density (also called apparent density).
Another name for a Crowned figure, Flat Sliced figure (see Chap. 2.3.4). Produced by slicing across the heartwood.
Cut figures are friezes with mostly half Crowns. Sometimes called Heart instead of Crown.
The pores can only be recognised with a microscope, e.g. in Maple, Pear, Cherry, Birch, Beech, Elm (also called microporous, small-pored, fine-grained, close-grained, fine-textured). These woods have a uniform figure.
Coloured changes to the end grains of a log or the entire log if it is stored too long. Is facilitated by direct sunlight or excessive dryness. To prevent foxiness from occurring, the log is either waxed at the end grains or is sprinkled with water.
Stress cracks (radial end shake) originating in the middle of the trunk (pith). The location of the heartwood crack is decisive in dividing the log for slicing. Heartwood cracks in the veneer are open and cannot be veneered.
The joining of consecutive veneer sheets from a pack (flitch) or an entire log to form a larger veneer area (face) is called veneer matching. Because of their direct, consecutive order, the veneer sheets have approximately the same figure.
Defect in the veneer, which forms holes. Loose knots, areas of rot, open heartwood cracks (heart shake), all have to be removed during processing. Solid deformed knots or branches are not open defects.
Black pin knots in Yew or European Beech veneers, which produce the typical figure of the Yew veneer. The more pepper and the more regular it is distributed over the surface, the higher the quality of the veneer.
Relatively large cells of deciduous trees. They are more or less visible in the cross-section as round or oval openings and in the longitudinal cut as pore grooves or needle cracks. Their size, number and distribution is species specific.
Method especially common for burl figured (masur) veneer, in order to produce highly decorative areas and figures (fancy pattern, patterned figure). Four consecutive veneer sheets are matched twice and folded up once.
Anomalous wood tissue, which has a negative effect on the useful value of the wood. The compression wood of the coniferous trees can be recognised by its high proportion of dark coloured latewood. The tension wood of the deciduous trees appears with a lightly silver shine.
The outer, light-coloured part of the wood between the bark and heartwood. In heartwoods different colour of the sapwood. The sapwood is usually cut off for veneers. In the case of several wood species, e.g. Palisander and European Walnut, the sapwood is used for decorative purposes.
Depending on the cutting angle used for slicing, the cells of the medullar rays become visible in different ways. Visual interruption in the overall pattern, which is desirable in several wood species, e.g. Plane tree. Particularly marked in Oak.
General name for dark, solid colour changes that have formed. Depending on the wood species and cause, a differentiation is made between gum, hairs, resin pockets, bark ingrowth, sugar, etc. Also called spatter or spots.
Spiral growth of a tree, which is caused by external effects, e.g. wind. Severe spiral grain can cause matching problems because the annual rings detach from each other and leave open spaces, which is why they are mostly sawn.
Different growth zones and growth speeds (weather side) in a trunk cause density differences to occur, which can cause stresses in the roundwood (log). If the tree is felled, stress cracks can occur, which call into question its suitability for veneer. Problem especially in Beech.
Set of standards commonly recognised in the timber industry in which general rules are defined for the sawing and veneer industry (e.g. quality designations for sawn wood, tolerances regarding veneer thicknesses and defective sheets, etc.).
Zones formed by irregular annular ring build-up in coniferous trees, which are particularly hard and therefore cause difficulties during veneering (compression wood, pressure wood, glassy wood, redwood, hard streaks, bullwood).
Thickness fluctuations caused by vibration of the veneer block on the slicing machine or incorrect pressure setting at the machine, which are regularly spread across the veneer sheet as cross-wise stripes.
Ribboning running in a direction across the tree axis in a tangential direction, with wavy fibre and annual ring development. Produces an irregular veneer match (see Variegated figure, Flake) (also called Curly figure).