The standard finish is violin oil varnish, hand applied by an animal hair brush. It dries partly by evaporation of the turpentine and other thinners, but later primarily by the oxidation of the oil components, such as linseed oil. This process can last for up to several months, even while the instrument is already in use. The satin or semi-gloss varnish surface stays softer and is known for its flexibility and durability.
The French polished spirit varnish is a traditional finish used even on pre-war Gibson mandolins. Its surface is harder and can look more glossy than the oil varnish, but it is less durable and may be easily damaged by water and especially by the player’s sweat.
The neck is mostly without varnish, treated solely by linseed oil.