Woodgrain express the alignment, texture and appearance of the wood fibres. A woodgrain texture that has many highly variant bundles of lines ranging from fine to coarse that run roughly parallel to each others, sometimes interrupted by swirls and knots. This is often important in its effect on woodworking techniques. In describing the alignment of the wood in the tree a distinction may be made. Basic grain descriptions and types include straight, cross, spiral and interlocked.