How board grain orientation is defined
Learn how board width and length map to widthwise and lengthwise grain.
When defining grain on a board or finish, the width is the shorter dimension of the board and the length is the longer dimension.
Whether a finish is widthwise or lengthwise depends on how the physical board is purchased: if the grain runs parallel to the longer side it is lengthwise, if parallel to the shorter side it is widthwise.