Clearwood

This refers to timber that does not have any physical or visual flaws, defects or other imperfections, and thus is ideal for use on a musical instrument, such as a guitar. For high-end acoustics, this means a large, single piece of spruce or possibly cedar that has no knots or other visual blemishes. Two-piece tops, found on many Gibson and PRS guitars, can be made from smaller pieces of clearwood because they are cut down the middle and then glued side-by-side, which is called bookmatching.