The lightest finish is ultrathin satin. This open-pore nitrocellulose finish provides extremely good sound transmission. The satin finish is also nitrocellulose, but the pores are closed. A few more layers of lacquer are applied and the surface is finely sanded and matt-polished.
With high gloss, also nitro, we add a few more layers, which are polished by hand.
Shellac is the icing on a high quality classical guitar. The resinous secretion of the insect Laccifer are massaged by hand into the top in sheer endless repetitions and thus provide a natural shimmering shine. A good advice for the ones who want to tickle out a little bit more sound. Be aware that Shellac is, however, sensitive to scratching and heat and therefore dissolves easily where the hand rests on the top. Therefore it has to be revised regularly.