Button Lac
Button lac, the historically authentic form — pure, uncut, genuine.
For most of shellac's working history, all shellac was button shellac. Seedlac would arrive at the refiner, be loaded into long cloth bags, heated over a charcoal fire, and pressed by hand into thin sheets or molten buttons left to cool on a flat stone. Whether the melt was sheeted into flake or left as a fused button was a question of trade form, not chemistry. The button is what came out of the press when the press stopped.
That older way of making shellac has narrowed almost to nothing. Most commercial shellac sold today is dewaxed flake — a twentieth-century industrial form, chemically distinct from anything the early finishing manuals describe. Button lac is still made, but in steadily fewer places. It is produced as a cottage industry now: in homes and small facilities in India, by hand, by people whose families have done this work for generations. Most commercially available button lac is adulterated with rosin to bring the cost down. Pure uncut button lac is sourced through trusted cottage producers, by people who know which producers can be trusted.
That is the shellac on this page.
What the heat does
When seedlac is melted to make button lac, the heat doesn't just shape the resin — it changes it. The shellac thermally pre-polymerizes during the press, producing a film harder and more durable in use than what cold-processed shellac yields. The 5–6% natural wax that is in every form of unrefined shellac stays in the button. It is not dissolved out; it remains inside the resin as part of the structure of the dried film.
This is the chemistry that working finishers have leaned on for centuries, well before anyone could measure it. The hardness is real. The film behaves differently. Practitioners describe it; the chemistry is consistent with the description, even where it has not yet been measured directly.
Who uses it
Floor finishers — button lac is the traditional choice for shellacked floors and interior woodwork, where the harder film earns its place under foot traffic.
French polishers — particularly those finishing musical instruments, where button lac produces the deep, glassy, unmistakably old surface the technique was developed around. Most French polishing manuals written before the 1920s assume button lac as the default; the technique and the material grew up together.
Antique restorers and conservators — period-correct work on furniture and instruments from the eighteenth and nineteenth centuries calls for the material that was actually used. Modern dewaxed flake will not produce a finish indistinguishable from what is being repaired. Button lac will.
Instrument repair shops — guitars, violins, the whole stringed-instrument world. The traditional French-polish finish on a violin is button lac.
The varieties we carry
The grades we keep on hand span the tonal range from a light golden amber through a deep reddish brown. From lightest to darkest:
Super Golden Kusmi Button Lac — the lightest button we carry. Develops a rich golden amber on light-toned woods. Seasonal, limited.
Special Golden Kusmi Button Lac — a shade darker than Super Golden, a shade lighter than Kusmi #1. New variety for 2026.
Kusmi #1 Button Lac — caramel amber. Develops warm amber tones on mahogany, red oak, cherry, and Douglas fir. Our most widely used button grade.
Kusmi #2 Button Lac — a deeper warm reddish-amber-brown than the #1. Suits oak floors, craftsman paneling, and the wood trim of late-nineteenth-century homes.
Dark Jethwa Button Lac — deep, warm, dark amber. Excellent on darker woods and on the dark trim and floors of homes from the late 1800s into the early 1900s. One hundred percent pure shellac; an exclusive grade.
The right grade is the one that matches the wood and the period. Lighter buttons let the wood's own color show through warmly; darker buttons assert themselves more, the way a finish on an 1890s walnut sideboard ought to. Many practitioners keep two or three grades on the shelf and reach for the one the piece calls for. If you would like a recommendation for a specific job, an email or a phone call will get you a real answer from someone who knows the material.
Reference: the pound cut chart — dry weight per gallon, quart, and pint at the common working cuts. Useful when you are breaking a button for a French-polish session and weighing the flake into a fresh bottle.
Browse the grades below.
