The mystery of great Italian violins built in Cremona between 1620-1780 became a general question a long time ago. Many authors have written books and articles about the life and activity of Amati, Guarneri and Stradivari, about the unequalled violins until present time, violins that reach very high prices. The quality of wood, as much as the precise dimensions used by the Italian masters are known and have been reproduced in the last 250 years. One single thing has remained unknown, the prescription of the varnish, which has been maintained carefully, then gone with the death of the last Luther. The purpose of this book is trying to solve an "enigma", both cultural and scientific, which has been investigated for over 250 years. Until present time, no one succeeded to show luthiers a procedure of how to build a violin with a sound spectrum almost similar to the sound spectrum of the human voice, for a prolonged time interval. In this book, we show a solution to this by indicatingthe use of the primer and we provide a series of experimental results that prove the validity of our research.