IV The Back and Edges
It is not of importance whether the back be made in one or two pieces; nevertheless, Stradivarius seems to have given the preference to a divided back. I also consider it more advantageous, as, being joined, it offers greater resistance, and is not so easily pressed outwards on the sound-post side, as is the case with violins having the back cut in one piece. The edges of the mid-rib and corners should be 4 m/m. thick, whereas the upper and lower edges of the back (Fig. 1 ee/ee), gradually decreasing from the corners, become 1 m/m. thinner.