Interior Design

Some grades of wood used in the manufature of cheap headboards is mostly not up to the standard required for top grade joinery. Some wood grades have abnormal characteristics which makes them unsuitable to be used as “show woods”, but they are able to be usedin things like tufted headboards and cheap headboards for beds. The occurrence of abnormal characteristics will, by anyone who has had a little experience in examining wood, be readily recognized as belonging outside the category of typical occurrences. Mechanical wounding of the growing tissue of some species may cause the formation of certain structural characteristics which are absent in normal wood, for example, the traumatic or “wound” resin ducts in hemlock (Tsuga) and true fir (Abies). In these species, wounding may cause vertical resin ducts to be present in the wood and, especially in balsam fir, so close together that on transverse sections of wood the neighbouring ducts form short lines that follow the curvature of the annual ring. Examination of the specimen elsewhere than in the abnormal area will show that such structures are absent in normal wood. In common North American usage a burl is “a swirl or twist in the grain which usually occurs near a knot but does not contain a knot”, according to the current rules of the National Hardwood Lumber Association, which state that such burls “not containing unsound centers are admitted in the cuttings except when otherwise specified”. In this sense, therefore, a burl may be a blemish or even a defect. In another important meaning, the term “burl” signifies wood with a desirable ornamental figure. Such ornamental burls typically contain wood with interlocked or undulating grain and may also be more or less thickly spotted with structures resembling bird’s eye or small knots. According to English practice the term “burr” appears synonymous with this meaning of burl. Ornamental burls may, therefore, be parts of the tree particularly likely to show ornamental figure, such as the butt ends which contain wood with swirled or twisted figure owing to the proximity to large knots and other structural irregularities, or they may be eccentric growths induced in trees by the action of foreign organisms on the growing tissue so as to cause swellings by local acceleration and distortion of growth. Utilization of ornamental burls, usually by slicing in thin veneers and applying the figured wood for decorative uses, is a specialized field of industry. The growth of the tree may cause foreign materials to be completely enclosed by wood, with considerable distortion of the surrounding wood structure. For example, a tight metal band about a tree trunk may, by constricting the conductive passages of the inner bark, cause local congestion of the descending food material, with the result that the trunk becomes swollen by the growth of wood just above the constricting band, which may become entirely enclosed by layers of wood that in the course of time literally “flow” over the obstruction. Such foreign objects as chains, scythes, and horseshoes, hung over branches and forgotten, are sometimes found embedded in, and so deeply overgrown by, wood as to be near the centre of large branches, while the occurrence of nails and spikes far in the interior of butt logs is a common source of difficulty to sawyers. Investigation of the exact processes of growth that take place in the cambium seems necessary to obtain information on the mechanism of the production of some abnormalities in wood. Parasites, both plant and animal, produce certain modifications of wood structure, known as galls, by stimulating the cambium to accelerated and specialised growth locally. While various forms of gall are known, the mechanism of their production is not completely understood. The presence of Sanio’s trabeculae’ in association with, bird’s-eye, abnormally enlarged resin ducts, and various structural abnormalities that have not otherwise been accounted for, indicates the presence of filamentous fungous parasites in the cambium of growing trees as the primary cause of these peculiarities. In hardwoods, small “pith flecks” are sometimes found. These flecks are usually visible as small definite brown lines or streaks in the direction of the grain, and are seldom sufficiently numerous to constitute an important blemish. They are usually visible for an inch or more on planed surfaces and have been named pith flecks because of their superficial resemblance to the brownish pith. Such streaks are caused by mechanical damage to the cambial tissue by the larvae of small species of beetles which bore tunnels in the cambium. The tunnelled wood is replaced by irregular brownish cells, after which the repaired cambium forms normal wood, resuming its activity and producing the wood elements in the same sequence that obtained before the insect attack, so that the principal rays usually have identical spacing in the wood inside and outside the fleck. These flecked woods are ideal for cheap headboards as they cost less, which is what you would expect when buying a a cheap headboard.