The History of Shellac, Part 2: A Brilliant Century

The History of Shellac — a four-part series
Part 1: An Ancient Resin · Part 2: A Brilliant Century · Part 3: A Fading Shine · Part 4: An Enduring Finish

The Shellac Century: 1820–1920

Two innovations drove the eventual widespread popular adoption of shellac in woodworking, and they came together in the early decades of the nineteenth century.

The first was bleaching. German chemists working in the Rhine valley — in the shellac-refining centers around Mainz — developed chlorination processes that could strip the red-orange color from shellac, producing pale and eventually near-colorless grades. This was an industrial breakthrough. Once pale shellac was available, the full range of cabinet wood species became viable substrates. The limitation that had kept shellac out of the finest workshops vanished.

The second was the codification of French polishing. The technique — applying shellac dissolved in alcohol with a small cloth pad, in thin successive layers, building up to a deep, grain-filled, mirror-bright surface — had been practiced on the continent for some years. Around 1810, it entered England from France, and within a decade it had spread through the British furniture trades. George Siddons documented it in The Cabinet Maker's Guide, first published in 1825, with an American edition following in 1827. By 1830, French polishing had largely displaced oil finishes on fine furniture across Britain, France, Germany, and urban America. By 1850, it was near-universal for quality work. The shellac era had arrived.

William Zinsser, who had trained as a foreman in one of those Mainz bleacheries, emigrated to the United States and in the 1840s established what would become the most influential shellac manufacturing operation in America. The Zinsser name became synonymous with refined, consistent shellac — the beginning of a lineage that eventually produced the small booklet The Story of Shellac (1913, revised 2004), a useful popular history of the material.

Within the shellac century, one product occupied a specific and recognized place: button lac. Button lac is shellac in its historically authentic physical form — seedlac placed in cloth bags and pressed over heat, the molten resin forced through the weave and falling in thick drops onto a cool surface, hardening into discs roughly the size of a button or small puck. The name is entirely descriptive. The product is what it looks like.

For most of the shellac century, the distinction between "button lac" and "flake shellac" described only the physical form after the same thermomechanical process — buttons left as buttons, or sheeted and broken into flakes. Both were products of the same bag-and-fire method. In the British furniture trade, dissolved button lac — sold ready-mixed as "button polish" — was a standard supply-house item used as a ground coat and in restoration work for its warmth and depth. The major British polish manufacturers whose names survive into the present day trace their button polish lines back to roughly this era.

The Adulteration Problem, Then and Now

One theme runs through the historical shellac trade so persistently it deserves its own note: adulteration. Rosin — the brittle residue of turpentine distillation — was the adulterant of choice. It was cheap, dissolved in alcohol, and produced something that looked like shellac until it was on the work. Adulterated shellac dried softer, spotted more easily, and produced less gloss. The trade literature of the late nineteenth and early twentieth centuries was explicit about the problem. Walker and Steele, in their 1922 Bureau of Standards technical report on shellac, spent considerable effort developing improved analytical methods precisely because existing tests could not reliably detect rosin adulteration at moderate levels. Even today, detecting rosin adulteration in refined shellac is not straightforward — part of why controlling the source matters as much as testing the result.

Button lac was particularly vulnerable, for a structural reason: its cottage-industry production — small operators, fragmented supply chains, difficult to audit — made it easy to incorporate adulterants invisibly. The implication for any serious buyer was the same then as now: purity requires controlling inputs at the source, not just testing outputs. The relationship with the producer, and specifically with the seedlac going into the bags, is the actual guarantee.

Next week — Part 3: A Fading Shine. Nitrocellulose, the phonograph record, and the long contraction that nearly ended the trade.