Varnished surfaces are common on antique furniture. This is a high-gloss and hard coating which is transparent enough to show the nervure of the wood. It was applied from the end of the 17th century to the 1920-30s, until the appearance of artificial lacquers.
Shellac is an animal-origin resin, the phlegm of the lice called Laccifer lacca, living on trees. Varnish is the alcoholic solution of this. Its color range is from yellow to brown.
The surface of the furniture has to be prepared properly for varnishing. The wood is grinded in several steps with more and more fine grinding paper. The surface is burnished for reaching the desired color then the next step is immersing with vegetable oil. The latter highlights the nervure of the wood. The pores of the wood are sealed during priming. A completely flat surface is created by using pumice-dust and 7% varnish. The first polish is done after drying with a so-called varnish ball and 7% varnish. The second polish is done after grinding, with 5% varnish. The final polish is done with 2% varnish and polishing ball (e.g. linen, industrial cotton wool, raw wool). The polishing is actually the removal of the oil from the layers. This gives the final shine of the furniture.
Varnish is a very durable and noble but expensive and sensitive surface. The direct sunshine and heat (for example near the radiator) can harm it. It needs proper care: only alcohol and solvent free detergent can be used and avoid wax and silicone-containing products. It mustn’t be cleaned with wet rag. Remove dust it with a soft cloth. Repairing of the injured varnish is a time-consuming task, leave it to a professional.
Ask for help of an interior designer for placing your antique furniture properly, even in modern surroundings.