
Wood grain is the longitudinal arrangement of
wood
Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin t ...
fibers or the pattern resulting from such an arrangement. It has various derived terms refer to different aspects of the fibers or patterns. Wood grain is important in woodworking and it impacts aesthetics.
Definition and meanings
Wood grain is the longitudinal arrangement of
wood
Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin t ...
fibers or the pattern resulting from such an arrangement.
R. Bruce Hoadley wrote that ''grain'' is a "confusingly versatile term" with numerous different uses, including the direction of the wood cells (e.g., ''straight grain'', ''spiral grain''), surface appearance or
figure
Figure may refer to:
General
*A shape, drawing, depiction, or geometric configuration
*Figure (wood), wood appearance
*Figure (music), distinguished from musical motif
* Noise figure, in telecommunication
* Dance figure, an elementary dance patt ...
,
growth-ring placement (e.g., ''vertical grain''), plane of the cut (e.g., ''end grain''), rate of growth (e.g., ''narrow grain''), and relative cell size (e.g., ''open grain'').
[Hoadley, R. Bruce. "Glossary." ''Understanding Wood: A Craftsman's Guide to Wood Technology''. Newtown, Conn.: Taunton, 1980. 265. Print.]
Physical aspects
Grain in growing wood follows the grown fibres of the timber and is mostly, but not entirely, longitudinal to the trunk of the tree. This can be influenced in branches, where the effect of gravity on the branch can distort the regularity of timber structure, compared to a vertical trunk. For this reason, branch wood is often not usable, or is of less value.
Growing

In describing the alignment of the wood in the tree, a distinction may be made. Different tree species may have one of the following basic grain descriptions and types:
* ''straight'' - grain which runs in a single direction, parallel to the axis of the tree.
* ''spiral'' - grain which spirals around the axis of the tree.
* ''interlocked'' - grain which spirals around the axis of the tree, but reverses its direction for periods of years resulting in alternating directions of the spiral grain. On
quartersawn surfaces the change in grain direction creates a ribbon stripe figure.
* ''wavy'' - grain which grows in a wavy fashion up the trunk; seen best in
flatsawn sections of wood.
* ''irregular'' - grain that swirls or twists. It can be found in a number of different patterns. This can be caused by factors such as knots, burls or "crotch" wood - where large branches separate from the trunk.
Aesthetic
In most timber, the grain of the timber is not the primary aesthetic feature. This is instead the ''figure'' of the timber, which is produced by the annual growth rings. In most timber, especially deciduous hardwoods, this is much more visible than the grain.
Mechanical strength
The two categories of grain in a piece of sawn timber are straight grain or and cross grain or . Straight grain runs parallel to the longitudinal axis of the piece. Cross grain deviates from the longitudinal axis in two ways: spiral grain or diagonal grain. The amount of deviation is called the slope of the grain.
Bulk timber is much stronger along the grain, so a finished piece with long grain will be much stronger than one with short grain. Much of
joinery is about techniques to manage this and to avoid having pieces with short grain.
Furniture
Furniture refers to objects intended to support various human activities such as seating (e.g., Stool (seat), stools, chairs, and sofas), eating (table (furniture), tables), storing items, working, and sleeping (e.g., beds and hammocks). Furnitur ...
, especially
chair
A chair is a type of seat, typically designed for one person and consisting of one or more legs, a flat or slightly angled seat and a back-rest. It may be made of wood, metal, or synthetic materials, and may be padded or upholstered in vario ...
s, has developed traditional designs to resist breakage by careful orientation of the grain. In shipbuilding, curved construction is often needed and so
knee
In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia (tibiofemoral joint), and one between the femur and patella (patellofemoral joint). It is the largest joint in the hu ...
s would be chosen when growing, from branches or branch junctions with a trunk, and then these could be incorporated into a design to match their natural curved grain to the curve of the finished component.
Woodworking
An important physical aspect of wood grain in
woodworking
Woodworking is the skill of making items from wood, and includes cabinetry, furniture making, wood carving, joinery, carpentry, and woodturning.
History
Along with stone, clay and animal parts, wood was one of the first materials worked b ...
is the grain direction or slope (e.g., ''against the grain''). In describing the application of a woodworking technique to a given piece of wood, the direction of the technique may be:
* ''with the grain'' (easy; giving a clean result)
* ''against the grain'' (heavy going; giving a poor result such as chipping or tear-out)
* ''across the grain'' (direction of cut is across the grain lines, but the plane of the cut is still aligned with them)
* ''end grain'' (at right angles to the grain, for example trimming the end of a plank)
Woods with straight grains are the easiest to work, while woods with interlocked grains are the most difficult.
Support
Grain alignment must be considered when
joining pieces of wood, or designing wooden structures. For example, a
stressed span is less likely to fail if tension is applied along the grain, rather than across the grain. Grain direction will also affect the type of
warping seen in the finished item.
Aesthetics

In its simplest aesthetic meaning, wood grain is the alternating regions of relatively darker and lighter wood resulting from the differing growth parameters occurring in different seasons (i.e.,
growth rings
Dendrochronology (or tree-ring dating) is the scientific method of chronological dating, dating tree rings (also called growth rings) to the exact year they were formed in a tree. As well as dating them, this can give data for dendroclimatology, ...
) on a cut or split piece of wood.
Figure
Figure may refer to:
General
*A shape, drawing, depiction, or geometric configuration
*Figure (wood), wood appearance
*Figure (music), distinguished from musical motif
* Noise figure, in telecommunication
* Dance figure, an elementary dance patt ...
in wood is produced by causes including fungus,
burls, stress, knots, and special grain alignments. Strictly speaking, grain is not always the same as the figure of wood. Figure rarity often promotes the value of both the raw material, and the finished work it becomes a part of. These include:
*
bird's eye
*
quilted
*
curly (fiddleback)
The way a given piece of wood has been sawn affects both its appearance and physical properties:
*
''flat-grain'': flat-sawn, slab-sawn, plain sawn, bastard-sawn,
[Punmia, B.C., Ashok Kumar Jain, and Arun Kumar Jain. ''Basic civil engineering: for B.E. / B.Tech first year courses of various universities including M.D.U. and K.U.'', Haryana. New Delhi: Laxmi Publications, 2003. 78. Print.] or sawn "through and through".
* ''edge grain'':
quarter-sawn
Quarter sawing or quartersawing is a woodworking process that produces quarter-sawn or quarter-cut boards in the rip cutting of logs into lumber. The resulting lumber can also be called ''radially-sawn'' or simply ''quartered''. There is wides ...
or
rift-sawn or straight-grained, and
* ''end grain'': the grain of wood seen when it is cut across the growth rings.
There is irregular grain in
burr wood
A burl (American English) or burr (British English) is a tree growth in which the grain has grown in a deformed manner. It is commonly found in the form of a rounded outgrowth on a tree trunk or branch that is filled with small knots from d ...
or burl wood, but this is result of very many knots.
See also
*
Grain painting
Graining is the practice of imitating wood grain on a non-wood surface, or on relatively undesirable wood surface, in order to give it the appearance of a rare or higher quality wood, thereby increase that surface's aesthetic appeal. Graining ...
*
Grain filler A grain filler (pore filler or paste wood filler) is a woodworking product that is used to achieve a smooth-textured wood finish by filling pores in the wood grain. It is used particularly on open grained woods such as oak, mahogany and walnut whe ...
*
Wood finishing
Wood finishing refers to the process of refining or protecting a wooden surface, especially in the production of furniture where typically it represents between 5 and 30% of manufacturing costs.
Finishing is the final step of the manufacturing p ...
References
{{DEFAULTSORT:Wood Grain
Grain
A grain is a small, hard, dry fruit (caryopsis) – with or without an attached husk, hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and ...
Grain
A grain is a small, hard, dry fruit (caryopsis) – with or without an attached husk, hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and ...
Wood