In 1879, a business contact of Joseph Pointet, a Lyon native whose brothers worked at the Bonnet silk house, approached him to secure some fabric through his connections: ‘Do what you think is best. Since you are well placed at Bonnet, you might be able to get something better than what you’d find at Poncet. But I prefer a true black—not red like the enclosed sample, and not blue like Bonnet's cashmeres.’

It's worth noting that he was addressing to an expert in the field: Bonnet was the second-largest silk manufacturer in Lyon between 1830 and 1870, almost exclusively dealing in solid black fabrics.

The pursuit of the perfect black was, therefore, a major concern for Claude-Joseph Bonnet, the founder of the Bonnet silk house. At the start of the 19th century, the art of dyeing in the Lyon silk industry left much to be desired.

Creating a black dye involves blending several coloured substances like yellow, blue, or red. Depending on which colour is emphasized, the resulting black may have hints of green, blue, or red. By carefully balancing these proportions, it is possible to achieve the deepest black, free from any other colour tints.

Until the early 19th century, the process of dyeing black—similar to making writing ink—relied on tannin-rich materials that would precipitate when combined with iron salts, forming the black dye. However, the results were often disappointing, either due to flawed techniques or the addition of unnecessary or harmful substances. The traditional method, which came from China through Italy, used gallnut black—a fixative with an expensive formula that resulted in an unattractive reddish tone.

The first half of the 19th century saw significant progress in black dyeing techniques, spearheaded by manufacturers like Claude-Joseph Bonnet. Logwood black, known for its bluish tint and referred to as ‘fine black from Lyon,’ was especially prized for its beauty and purity, reinforcing Lyon's dominance in the silk industry. In 1810, the French chemist Michel-Eugène Chevreul had isolated hematoxylin, a red dye extracted from logwood, which enabled him to create a high-quality black dye by combining it with chromium salts. It was with this dye that the renowned dyer François Gillet began to make a name for himself.

In the 1850s, new fixatives, which François Gillet excelled in using, brought about ‘cachou black’ or ‘mineral black,’ which was less red than gallnut black and did not damage the silk. Later came ‘henna black’ or ‘African black,’ an incredibly rich and durable black. Additionally, as early as 1833, Prussian blue was incorporated into black dyeing, producing a bluish-black known as ‘imperial black,’ which remained in vogue from 1859 for at least fifteen years.

Claude-Joseph Bonnet's relentless commitment to quality—bordering on obsession—earned him numerous accolades at the world’s fairs. The company received two bronze medals in London in 1851 and 1862, a silver medal in Paris in 1867, a gold medal in Porto in 1865, and the grand prize in Paris in both 1878 and 1889.