Ninety percent of all furniture finishes before World War II are shellac. It is the most versatile, forgiving, easily applied, and beautiful finish there is. After the war the dominant finish became lacquer, nitrocellulose; in other words, plastic. Shellac became popular in the nineteenth century, replacing oil or beeswax finishes in the 18th century. Shellac dries fast, can be applied with a brush or rag, can be high gloss or a satin sheen, is a very good UV protector and is long lived. In addition, it enhances the beauty of most every wood it is applied over due to its excellent optical properties.
Shellac is an insect product, derived from the lac bug of Southeast Asia and India. The accumulated residue of excretions of millions of these tiny insects provides the raw material for shellac production. These are dissolved by alcohol and refined to different degrees in color and wax content determined by use.
The other resin finish used in the last 200 years is varnish. Varnishes are very hard, slow drying finishes made from fossilized tree resins. These natural deposits are similar to amber but not as old, and are very difficult to create and apply. It was most often used for table top finishes due to its depth and durability. It was also used as a top coat over shellac to try to reproduce the effect of Oriental lacquer, a material unattainable to the European craftsmen. It is the traditional finish on spars and bright work on boats.
A working knowledge of old resin finishes is essential to their conservation on antique furniture. Many contemporary furniture makers are returning to the resin varnishes for their new creations after discovering their fine qualities.