Spruce is the soft acoustic wood used in instrument making. 90% of the sound comes from the spruce. Spruce is the lightest wood for the amount of strength it has, making it the perfect wood for acoustic instruments.  Violin wood used for the tops of the instruments is almost always quarter-cut. A pie cut is taken from a log, divided in half, and then joined together. This gives you the flat bottom and beginning of the arching for the top. The grain is perpendicular to the plate.  Once the top is formed, purfling is inlaid around the edges of the top. This is not just decorative, it also protects the top from cracks – in the event of a strong impact to the edge it will keep a crack from spreading past where the purfling has been inlaid.  Maple is what we most often use for the backs of instruments. Instead of quarter-cut, this is a slab-cut. The tree trunk is cut length wise, leaving the grain in the opposite direction of the quarter-cut top. Having the grain this direction is ok for the back, as the maple is a much stronger and heavier wood than the spruce used for the top.  The two main woods used in instrument making are spruce and maple. Although slab-cut maple was shown here, we do often use quarter-cut maple as well, but are always happy to be able to use a slab-cut piece!