Varnish is not simply essential for the acoustic output, but it is also the instrument’s artistic and personal signature. This is the reason why varnishes made with natural resins (coppali, damar, sandracca, etc., mixed up following recipes passed in time from master to apprentice) are used, supporting wood’s fibres natural vibration, and considered the best mixtures for the finish of a musical instrument. Moreover, the method of varnish application is very industrious, because the technique of brush hand painting needs a long period of learning - and it amplifies the styling differences amongst luthiérs becoming a sort of personal and unique touch. In fact these varnishes are the only ones used for violins, cellos, etc. Depending on the inevitabile different structure and use of guitars, compared with bowed strings instruments, is used a more appropriate mix, harder and more resistent.
Varnish can be glossy or satin. Satin is adviced for lighter colors (as natural, or amber color), while darker colors (from violin-brown to black of Dark Lorraine) are improved by glossy finish. Anyway the difference between glossy or satin is exclusively a matter of aesthetics, since both quantity and quality of varnish is the same. When a harder varnish is required, is possibile to use a synthetic water-varnish as final application, which allows all the aesthetic and acoustic characteristics of the natural finish can be manteined.