Differences between shellac and varnish

The words that we talk about, that is, shellac and varnish, are both related to furniture and we may have or will surely come across them when ordering or buying furniture for our house. The two represent similar things but there are differences between the two and it is not correct to use the two interchangeably. As we will now point out there are certain factors that can distinguish the two.

Furniture these days is available in various materials such as wood, teak etc. It is very common to have a top or finish on that material to improve the life of furniture, make it durable and preserve its elegant look. The terms varnish, shellac, lacquer and polyurethane are commonly used to refer to the final finishes we are talking about.

Let us first look at what they exactly are. Shellac is merely a resin that is secreted by the lac bug. It can be processed and then sold as dry flakes. It can then be used as a brush-on colorant and most commonly as wood finish. Varnish, on the other hand, is a protective finish or film that is very hard and is also used in wood finishing. It is used for the finishing of other materials as well. Traditionally, varnish is prepared by making a combination of a resin, drying oil and a solvent or a thinner.

There is also significant difference in the origin of the two. As mentioned, shellac comes from the secretion of the female laccifera lacca which is rarely found anywhere other than Southeast Asia or India. Initially, it was used as a dye; then for the very first time in 1590, it was used as a finish in India. Insect secretions were collected from tree trunks and were dissolved in alcohol. In contrast to this, varnish was first prepared and used by the Egyptians. They used tree resin and dissolved it in turpentine, also a solvent that comes from trees. The result was an amber-coloured material that could be used for finishing. It takes time to dry but once hardened, provides reliable protection for a long time.

Moving on, a very important difference between the two is that varnish cures as it dries. This renders the finish impervious to solvent that is reapplied. Shellac, on the other hand, when dried, dissolves readily once it is moistened with alcohol, fresh shellac or lacquer thinner. Another difference would be that a coating of varnish is heavier than that of shellac. Therefore only one or two coats are applied. This is not the same for shellac in which several coats are applied as undercoats of shellac dissolve and then bind to fresh coats. This also somewhat accounts for the difference that a completed shellac coating is usually softer than that of varnish.

In recent times, both shellac and varnish have evolved from their conventional forms. Modern varnishes come with a drying agent, an example being linseed oil, which is carried in mineral spirits and not turpentine. Modern shellac is more similar to its conventional form; rather there is hardly any difference between the two. It is still available as flakes that can be dissolved by the user as well as a pre-mixed pack.

The differences between the two account for various ways in which the two can be used. Due to the fact that it cures and has a harder coating, varnish provides greater protection. This is the reason it is used for exterior use, floors, interior woodwork and furniture that is used a lot or exposed to dust, wind, and pollen etc. Shellac, however, is more suitable for cabinet, antiques and table tops. It gives an elegant look and is easier to apply.

Summary of differences expressed in points

1. Shellac-a resin secreted by the lac bug, can be processed and sold as dry flakes; Varnish-a protective finish/film, very hard, used in wood finishing; Traditionally, varnish is a combination of resin, drying oil and solvent/thinner

2. Origin- shellac; the secretion of the female laccifera lacca found in Southeast Asia or India; varnish; first used by Egyptians, dissolved tree resin in turpentine, result-an amber-coloured material used for finishing

3. varnish cures as it dries; shellac- when dried, dissolves readily after it is moistened with alcohol

4. Coating of varnish is heavier and harder than that of shellac

5. Varnish provides greater protection

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