Common Questions About Shellac
The questions we get most often, answered plainly.
Is shellac old-fashioned?
Yes, in the sense that the Indian subcontinent has been working with it for five thousand years and Europe has been finishing furniture with it since the sixteenth century. No, in the sense that it is still the right finish for a great deal of work — conservation, instrument repair, restoration, fine furniture — for reasons no modern coating has displaced. It is reversible, non-toxic, food-contact safe, fast-drying, and forgiving. Few modern coatings offer that combination.
The defense of shellac is not nostalgia. The defense is that nothing else does what shellac does.
Is shellac really made from bugs?
Shellac is a natural resin secreted by the lac insect (Kerria lacca) as it feeds on host trees in India and Southeast Asia — most commonly the Kusum tree (Schleichera oleosa). The resin forms a hard, protective coating on the branches; that coating is what is harvested, refined, and sold to you. Roughly 100,000 insects produce one pound of resin.
The bug-droppings framing is wrong on two counts. Shellac is a secretion, not waste. And calling it “bug-derived” obscures what it actually is: a structural protein-and-wax matrix that the insect builds, in the same general category as silk from a silkworm or honey from a bee. Materials of biological origin, refined for human use, with traditions of practice going back millennia.
Will shellac yellow or darken with age?
Far less than the finishes people usually worry about. Oil-based varnishes and polyurethanes yellow noticeably as they age; shellac holds its color much better, which is one reason conservators reach for it on pieces meant to last. The dewaxed pale grades in particular stay close to true.
That said, shellac is a natural resin, not a color-locked plastic. Over long exposure — especially to strong, direct sun — a clear film can warm slightly, and the naturally colored grades carry their tone from the first coat. The very dark shellac you sometimes see in old houses is usually one of those darker grades, or a finish the maker tinted when dark wood tones were in fashion — not clear shellac that turned brown on its own. Used indoors, out of constant direct sun, a shellac finish stays remarkably true for decades.
Does shellac scratch easily?
Less than lacquer. The film is durable enough for floors and tabletops, and where damage does occur, the repair is unlike anything else on the market: a fresh coat of shellac dissolves into the existing coat and bonds chemically with it. The repair is invisible. There is no sanding-the-edges-and-hoping. There is no witness line.
Conservators value this property above almost any other. A two-hundred-year-old shellac finish can be brought back to life with a rubber and a bottle of alcohol. A modern catalyzed finish, when it fails, fails permanently.
Is shellac water-resistant?
In ordinary household conditions, yes. A properly applied shellac finish — three or four coats, fully cured — will resist water for hours of contact without blushing. We use shellac on floors, tabletops, doors, paneling, and interior trim.
The qualifier worth stating: water-resistant is not waterproof. Prolonged contact with standing water — a sweating glass left overnight, a flower vase that drips — can produce a white bloom in the film. That bloom usually polishes out. It is not a sign that shellac is the wrong finish; it is a sign that the finish needed a coaster.
Is shellac compatible with other finishes?
As a rule, yes — shellac adheres to almost any clean, wax-free, oil-free finish, and almost any clean finish adheres to shellac. This is part of why it is so widely used as a sealer.
One exception worth knowing: wax-containing shellac (regular shellac, button lac, seedlac) may not be compatible as a sealer under certain polyurethanes — the natural wax in the resin can interfere with adhesion. If you are sealing under polyurethane specifically, use a dewaxed grade. For everything else, the wax presence is not the problem.
A note on practice: instrument and conservation work generally stays inside the shellac system rather than layering modern coatings on top. Shellac repairs shellac; polyurethane does not.
What is button lac, and how is it different from flake shellac?
Button lac is the historically authentic form of shellac. For most of shellac's working history, every grade was thermomechanically processed — melted, sheeted, and either pressed into discs (buttons) or broken into flake. The wax was left intact. What conservators, historic-finishing practitioners, and many French polishers consider the traditional, period-correct form is this one.
Modern dewaxed flake is a twentieth-century industrial development, distinct from anything Stalker and Parker described in 1688 or any of the period finishing literature. Dewaxed flake is excellent material — clearer, harder, more workable for some applications — but it is not the same material as button lac, and the two should not be treated as interchangeable for period-correct work.
The natural wax content in button lac is 5–6%. The figure of 25% that circulates in some forums is a measurement artifact, not a real number — likely from practitioners filtering dissolved button lac and visually estimating volume.
How do you dissolve shellac?
In denatured alcohol or 190-proof ethanol. Higher-proof alcohols dissolve cleanly; anything containing water will dissolve poorly and leave you fighting the mix.
Cuts are described by weight: a pound cut is one pound of dry shellac in one gallon of alcohol. A 2-pound cut is two pounds in one gallon, and so on. The cut you want depends on application — French polishing typically wants a thinner cut (1- to 1½-pound), brushwork tends toward 2- to 3-pound, padding sits in between. We do not recommend a specific cut. The practitioner chooses the cut to fit the technique. The Pound Cut Chart is provided as a reference; the decision is yours.
Mix only what you will use within about three months. Dissolved shellac has a working life; over time, the resin in the bottle loses some of its hardening properties.
How long does shellac keep?
Dry flake, stored cool and sealed, lasts a long time — years, in most cases. Dewaxed grades hold longest; wax-containing grades shorten somewhat as the natural wax ages, though for practical purposes the difference rarely matters before the bag is gone.
Dissolved shellac is the shorter clock. Three months is a reasonable working assumption. If the dissolved cut becomes sticky on a test panel, or if a dry coat stays tacky past the usual cure window, the alcohol is fine but the shellac is past its useful life. Throw out the cut and mix fresh.
This is also why we sell flake rather than pre-mixed liquid shellac. You mix what you need, when you need it, and what you don't use stays in dry form on the shelf.
Why so many grades?
Because shellac is a natural material, and natural materials come from different trees in different regions in different seasons with different colors and properties. The grades — Kusmi, Bysakhi, Jethwa, Lemon, Garnet, Black, Blonde — are the way the trade describes those differences.
In broad terms: the lighter grades (Blonde, Platina, dewaxed pale) are more refined and clearer in film. The darker grades (Garnet, Seedlac, Button) carry more of the original color and more of the practitioner's full toolkit of warmth, working time, and depth. Wax-containing grades behave differently from dewaxed grades. Seasonal grades — harvested at different times of year — vary in color and chemistry.
There is no single best grade. There is the grade that suits the work in front of you. Knowing which is which is part of the craft.
If a question you have isn't covered here, we'd like to know. The most useful additions to this page come from practitioners working through specific problems on specific pieces.