Wood is a remarkably beautiful and resilient material. Just as each tree is unique depending on age, soil nutrition, and weather patterns in its environment, each and every plank of wood is different – sometimes even through the same tree. Adding to this huge variety of expressions are some rarer occurrences which affect the look of the wood.
When a tree is infected by a virus or parasite, injured, or affected by abnormal growth, it responds by producing a large, convoluted nodule. When these are cut from the tree and sliced into slabs, a Burl pattern is revealed. These patterns are often very beautiful, with swirls, bullseyes, and wavy grain patterns, and they are often lustrous and shimmering, due to the density of the grain. Nodules are usually pretty small, so Burl veneers are very common. Burls can be found on almost any species of tree, but large nodules that can be made into workable slabs are most often found on Elm, Maple, Redwood, and Oak.
The shimmering bands formed by the compression of wood fibres are referred to as Curly grain. The sheer weight of larger trees put a great amount of pressure on the lower trunk wood, and the steady compression forms ripples and waves in the grain. Curls can also form in crotch wood (the wood at the base of two intersecting branches). Curl is most often found in Maple, Oak, Walnut, and Cherry, but can technically form in any hardwood.
A Live Edge on a plank refers to the edge where bark is attached. Finished boards will usually have these edges sawn off, but a resurgence in the popularity of Live Edge slabs means that they are readily available again. The bark is removed, the edge is sanded and finished, and the overall look is more natural and organic – especially compared to the sharp, planed edge of a processed board. Large Live Edge boards require special equipment to work, but small slabs can be easily managed in most shops.
Quarter Sawn boards are cut at an angle, rather than flat through the log, resulting in a different view of the wood grain. Quarter Sawing a log is more wasteful, as less of the log is able to be used, but cutting in this fashion produces a straighter grain and more stable board. Typically, Oak is Quarter Sawn, resulting in Tiger Oak, a shimmering pattern of stripes similar to Curly grain.
Some woods display a range of shades within the same board, especially between heartwood and sapwood, but for the most part, trees do not produce a wide variety of colours within the same wood. One of the exceptions is Rainbow Poplar. Poplar trees often grow in very wet environments, and the minerals that are dissolved in the soil are easily drawn up and absorbed by these trees, causing brilliant streaks and bands of colour along the length of the boards. Colours can range from pale bands of green, which are very common, to streaks of black or brown. The rarest Rainbow Poplars display a full range of colours, from reds to purples, golden hues to greens, and even blues – all within the same board!
Rainbow Poplar is usually reserved for small pieces of furniture, but I have seen at least one instance of a Rainbow Poplar hardwood floor, and one instance of Rainbow Poplar kitchen cabinets. While I don’t recommend the kaleidoscope of colour that results when covering such large areas with rainbow colours, I do enjoy Rainbow Poplar side tables, stools, desk tops, and drawer fronts. Like all woods, the colours will fade and turn brown given enough time, and finishing oils tend to dull the colour immediately, so the best finish for Rainbow Poplar is a clear coat of lacquer or polyurethane, which preserves the colour of the wood for a bit longer.
Reclaimed / Recycled
Any wood can be re-used, as long as there is enough of it left to be useful! Typically, planks of wood are reclaimed from flooring, old house and barn siding, and solid structural beams. The planks are de-nailed and then sawn or planed down to remove weathered and worn surfaces. The resulting planks can be used just like new ones. Weathering, nail holes, discolouring, scratches and cracks can all be features of this wood, but they can also be perfectly clean and clear.
The major benefit of using reclaimed wood is, of course, not cutting down a perfectly good living tree. Older wood has the added benefit of probably not being farmed, which means that the grain will be much tighter and the wood harder and more resilient than modern, farm-raised wood.
Spalted wood is like aged beef – the longer a log sits around exposed to moisture, the more fungus infiltrates the wood. Since the pores of the wood run along the length of the grain, the fungus can stain the wood in artistic lines and bands. The process is stopped before the wood essentially begins to rot, which requires perfect timing, and Spalted Wood is a beautiful, naturally created by-product. Spalted Maple and Birch are quire common.
Wormy wood is exactly as it sounds: wood that has been eaten through by insects. Though not necessarily worms per se, beetle larvae and other wood-loving insects bore little round holes through a log, and it appears as though little worms have passed through. Often found in Spalted woods, these tiny holes are perfect for rustic looking projects.