Shellac dissolved in spirit forms the basis of most spirit varnishes; the addition of resin is often advised on the score of cheapness. It also assists the varnish to flow level, gives it more body, and imparts a brightness not obtainable by the use of shellac alone. As excess of resin yields a varnish easily scratched, benzoin is added to make it harder, in addition to increasing its brilliancy, shellac and spirit alone will suit for some purposes as a varnish, but will generally need more shellac in than when for use as French polish to be applied by means of pads.