Wood grain

Wood grain describes the alignment, texture and appearance of the wood fibres. This is often important in its effect on woodworking techniques (e.g. against the grain).

In describing the alignment of the wood in the tree a distinction may be made. Basic grain descriptions and types include:

straight - grain which runs in a single direction along the cut wood, a product of a straight growing tree
cross - grain in which some cells grow out from the major growth axis of the tree
spiral - grain which develops as the trunk of the tree twists in development
interlocked (roey grain) A step beyond spiral grain occurring when growth rings in a twisting trunk develop misaligned grain

Maple burl, not to be confused with bird's eye maple

In addition, there are a few special grain alignments. Their 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
fiddleback
curly
tiger

In describing the application of a woodworking technique to a given piece of wood, the direction of the technique might be:

with the grain
against the grain
across the grain

In a wider sense, the term grain may also be applied to the orientation of the cut, the way a given piece of wood has been sawn:

flat-grain: flat-sawn or plain sawn,
edge grain: quarter-sawn or rift-sawn or straight-grained, and
end grain.