Many violin makers swear by their own secret recipes — often closely guarded.
The ground layer (for example, made from protein such as egg white or gelatin, or from minerals) is just as important as the varnish itself. It controls how deeply the varnish penetrates the wood and enhances the play of light across the surface.
Even the conditions during drying — temperature, humidity, and exposure to daylight or UV light — can have a decisive effect on the final result.