Bois Durci (translated from French as "hardened wood") is one of the earliest organic plastics and thermosetting composite materials in history, invented in France in the mid-19^th century. This material emerged long before the development of synthetic plastics based on phenol-formaldehyde resin.

The origins of the material trace back to 1855, when French poet and inventor François Charles Lepage patented a new compound that could replace wood and other hard plastic materials. Driven by the desire to find an inexpensive alternative to precious woods, primarily black ebony, Lepage turned his attention to waste from furniture workshops and slaughterhouses. He took wood sawdust and animal blood serum from these industries, combined the ingredients, and produced a dense, monolithic mass through heat treatment.

Despite the revolutionary nature of the idea, François Lepage himself was unable to establish stable industrial production due to technological difficulties. In 1859, he sold the patent rights to Alfred Latry, a French engineer and entrepreneur. Latry improved the technical process and founded a specialized company, "Société du Bois Durci", Grenelle, a suburb of Paris. It was Latry, who transformed the experimental compound into a successful, world-class commercial brand. His company's products achieved resounding success at the International Exhibition in London in 1862 and the Exposition Universelle in Paris in 1867.

From a technical standpoint, Bois Durci is a bio-composite based on a protein binder. Its manufacturing process involved several stages. First, the raw materials had to be prepared: the base of the material consisted of wood dust obtained from processing rosewood, ebony, and kingwood. Albumin served as the binding agent, which was sourced on an industrial scale from ox blood purchased at Parisian slaughterhouses. For more expensive items, egg white was sometimes used. Once all ingredients were ready, the mixing process began. The wood flour was stirred into fresh blood, after which the resulting mass was heated to approximately 45°C to remove excess moisture. The dried compound was ground into a fine, homogeneous powder, sometimes with added pigments, before being pressed in steel molds with hot steam for thirty minutes. High heat and pressure, often featuring intricate, embossed designs, allowed for detailed shaping, with subsequent cooling in water causing the blood proteins to coagulate and harden the Bois Durci objects.

As a result, the material turned out to be incredibly dense and heavy. Furthermore, it was heat-resistant. The material possessed a natural glossy sheen that required no additional polishing or layers of varnish.

Due to its durability, water resistance, and ability to take on any complex shape, Bois Durci found applications in many areas of daily and cultural life during the era of Napoleon III and Queen Victoria. For instance, the material was used to manufacture luxurious office and stationery supplies: inkstands, pen trays, pencil cases, and paperweights. One of the hallmarks of the Société du Bois Durci became its embossed wall plaques featuring portraits of historical figures, contemporary rulers, and mythological scenes, which were the pride of collectors. Additionally, the material was used to manufacture haberdashery goods: buttons, handles for walking sticks and umbrellas, durable combs, and smoking pipes. Larger household items were also made from Bois Durci – for example, photo and mirror frames, jewelry boxes, decorative furniture mounts, and doorknobs were highly popular. Thanks to its rich black color, Bois Durci even became an affordable substitute for scarce jet in Victorian mourning jewelry. The material was used to make brooches, lockets, necklace beads, and belt buckles, serving as tokens of remembrance for the loss being mourned by the wearer.

In 1898, the French corporation MIOM (La Manufacture d’Isolants et Objets Moulés) acquired Alfred Latry's enterprise. The new owners continued to produce items using the original molds, but the composition of the material underwent changes. By 1907, for reasons of hygiene, simplified logistics, and cost reduction, organic blood in the formula was replaced with natural plant-based shellacs, rosin, and the first synthetic resins.

Additionally, in 1883, Ambroise Chevalier opened his own factory in the town of Sézanne, which grew into a major competitor to Latry’s enterprise. His company produced items with a similar composition but in more fashionable Art Nouveau shapes.

By the end of the 1920s, the Bois Durci era had come to an end. Fully synthetic plastics entered the market; they required no organic components of animal origin, were cheaper to mass-production, proved more stable in use, and completely supplanted the old composite. In 1926, the factory of Chevalier’s successors burned down, items made of Bois Durci are recognized as an important milestone in the history of industrial design. Original 19^th-century pieces can be found in the world’s major museums, such as the Victoria and Albert Museum and the Science Museum in London. For antiquarians and collectors, authentic items hold immense value. Original products from Alfred Latry's factory can be identified by the maker's mark on the reverse side of the items, which is usually an impression of a bird's wing or an embossed "Bois Durci" inscription.

The museum "Collection" exposition features several snuffboxes, bonbonnières, and musical boxes crafted from Bois Durci.
These exhibits were created in the second half of the 19^th century in France and Switzerland. Their lids are still adorned with intricate compositions: still lives,  landscapes, mythological scenes, historical episodes, and even portraits of famous figures of the era – for instance, King Frederick William III of Prussia, Emperor Francis I of Austria, and Emperor Alexander I of the Russian Empire.