Spruce is used for the belly wood of a violin, being among the most relevant parts for the sound of the instrument. Violin builders only use spruce from mountainous regions where the temperatures are conducive to a more even and dense wood. Only the best sounding wood should be selected for top-quality instruments. Only wood that has been split or excised from the stem like a piece of cake, should be used. Our experience has showed that flawless and fine growth is not decisive for sound quality. The acoustic qualities of the wood alone, is all important. Even small branches in the wood can be acceptable. That the great violin makers of the 16th through 18th century were not deterred by small flaws in the wood can be seen in their instruments, which show uneven annual rings and branches. Yet these instruments have first rate tone quality. For wood types see also Wikipedia.