Cellulose nitrate was a semi-synthetic plastic used as the base material for motion picture film stock. One of the first plastics, it is highly flammable and chemically unstable, but its transparency, flexibility, and strength made it ideal for the new film medium. Nitrate film remained the global industry standard until the 1950s, when it was replaced by a “high-acetyl” cellulose acetate stock, commonly referred to as cellulose triacetate.

In 1846, German-Swiss chemist Christian Friedrich Schönbein combined cotton fibers with nitric and sulfuric acids, creating cellulose nitrate. The explosive material had obvious military applications (guncotton), but with chemical alterations also proved useful for other industries (del Amo, 2000: pp. 42–44). Key to the burgeoning field of photography were experiments with pyroxylin, a refined, non-explosive form of cellulose nitrate, with a lower nitrogen content. Dissolving pyroxylin in ethyl alcohol produced a colorless, viscous liquid called collodion, which was quickly adopted by photographers to adhere photosensitive emulsion to glass plates (Rossell, 2002: p. 38). Combining pyroxylin with solvents and plasticizers, particularly camphor, produced a transparent solid material that could be molded into shapes using heat, or pressure, and colored with dyes, fillers, or paints. First patented by English engineer Alexander Parkes in 1865 and sold under a variety of trade names, this new plastic was commonly called “celluloid”, thanks to Americans John Wesley Hyatt and Isiah Smith Hyatt. In 1872, the Hyatt brothers patented a superior manufacturing process and the following year, they relocated their business, the newly renamed Celluloid Manufacturing Company, from Albany, New York, to Newark, New Jersey, and soon dominated the market for pyroxylin-based plastics (Kaufman, 1963: pp. 17–40; Mossman, 1994: pp. 11–22).

Despite its well-known flammability, celluloid was used to make a range of products, including billiard balls, dentures, combs, shirt collars, toys, and decorative objects (Rossell, 2002: pp. 39-40). The material’s strength and transparency also made it suitable as a photographic base (Friedel, 1983: p. 91). In 1888, John Carbutt’s Keystone Manufacturing Company in Philadelphia, Pennsylvania, became the first supplier of celluloid photographic plates – manufactured using celluloid supplied by the Celluloid Manufacturing Company (Rossell, 2002: p. 41; Spehr, 2000: p. 5). Using a solvent called amyl acetate, patented by the Celluloid Manufacturing Company, Henry Reichenbach, chemist at the Eastman Dry Plate Company (later Eastman Kodak) in Rochester, New York, further refined the celluloid mixture to create a thin, flexible plastic base for Eastman’s new photographic roll film. Reichenbach filed a patent for his celluloid roll film in April 1889. (Friedel, 1983: p. 93; Rossell, 2002: pp. 42–3; Spehr, 2000: p. 6). In 1887, Reverend Hannibal Goodwin of Newark, New Jersey, had filed a similar patent, but issues with the amateur inventor’s descriptions of his processes delayed its approval until 1898. In 1914, after many years of courtroom battles, Eastman Kodak and a few other film manufacturers were found to have infringed Goodwin’s patent, then held by photographic wholesalers Anthony and Scoville (later Ansco). By this time, however, the patent had nearly expired and Eastman’s roll film business was firmly established (Friedel, 1983: pp. 93–4; Rossell, 2002: p. 50, n. 37). Eastman began manufacturing celluloid roll film in February 1890 (Rossell, 2022: p. 33). Their chief competitor, the Blair Camera Company in Boston, MA, began commercial production of their own photographic roll film in late 1891, using celluloid from the Celluloid Manufacturing Company (Spehr, 2000: pp. 3–28; Rossell, 2002: pp. 41–4). 

Celluloid roll film immediately proved useful for experiments in scientific and moving-image photography. Étienne-Jules Marey, for example, used Eastman celluloid roll film for demonstrations of his sequence camera in Paris, November 1890 (Rossell, 2022: p. 37). In 1899, W. K. L. Dickson also turned to Eastman for help in adapting celluloid roll film for the motion picture equipment being developed at Thomas Edison’s laboratory. The Kinetograph camera and the Kinetoscope viewer required narrower, thicker celluloid, able to withstand the camera’s stop-start movement as well as repeated viewings. After a great deal of experimentation, Dickson and Eastman settled on a filmstrip 35mm wide, which would evolve into the standard gauge for professional filmmaking (Spehr, 2000: pp. 7–21). In 1892, Eastman suspended roll film production due to personnel issues, and so Dickson ordered customized 35mm stock from the Blair Camera Company, to shoot the first Kinetoscope films, such as Blacksmith Scene (1893) and Sandow the Strong Man (1894) (Spehr, 2000: pp. 13–14). 

At the same time, the European Blair Camera Company, based in England, was supplying many early filmmakers overseas, including Robert Paul in the United Kingdom, the Lumière Brothers in France, and Oskar Messter in Germany. European Blair was founded in 1893 after a corporate restructuring, and though technically a separate company, it retained access to the patents and manufacturing methods of its American counterpart. Eastman resumed roll film production in early 1894, initially restricting moving image film to special custom orders. In 1896, in response to growing demand in America and Europe and increasing competition from Blair, Eastman began regular production of 35mm motion picture film, regaining Edison’s significant business (Spehr, 2000: pp. 18–19). Eastman Kodak then purchased American Blair in 1899, securing the patents for the company’s superior manufacturing methods, and becoming the largest producer of celluloid film in the United States (Rossell, 2002: pp. 43–5). Eastman also supplied nitrate film to many other parts of the world, with subsidiaries in Canada, England, France and Germany (Layton, 2020: pp. 240–7). 

Celluloid was both dangerous and difficult to manufacture, and suppliers were limited, particularly in the early decades of the film industry. A number of film stock companies entered the market, only to fold after a few years, while others, like Blair, purchased the celluloid base from an outside manufacturer and then coated it with proprietary emulsions (Rossell, 2002: pp. 44–5; Rossell, 2024). France first began nitrate film production in 1896, when the Lumière Brothers joined with sheet film manufacturer Victor Planchon, to found the Société des Celluloses Planchon in Lyon (Spehr, 2000: p. 17; Rossell, 2002: p. 45). Pathé Frères purchased European Blair in 1907, and manufactured its own stock until a merger with Eastman Kodak in 1931 (Salt, 1992: p. 63; Blot-Wellens, 2020: pp. 206–7). In Germany, Agfa (Aktien-Gesellschaft für Anilinfabrikation) began manufacturing moving image film around 1899, and merged with the American company Ansco in 1928. Ansco became independent again after World War II (Berriatúa & Blot-Wellens, 2020: pp. 257–8; Pritchard, 2020: p. 307). Gevaert, in Belgium, appears to have started manufacturing moving image film around 1910; while Ferrania in Italy, started in the mid-1920s; and the British photographic plate company Ilford launched its first film stock, Selo, in 1923 (Blot-Wellens, 2020, pp. 267–8; Pritchard, 2020: pp. 308–10). Efforts towards initiating domestic film stock production in the Soviet Union, began in 1926, initially with help from the French industry. The first factory in Pereslavl-Zalessky, Russia, began operating in 1931. Three others, located in Shostka, Ukraine; Kazan, Russia; and Leningrad, Russia, had opened by 1935. By 1937, the USSR claimed to be the third largest film stock manufacturer in the world (Bagrov, 2020: pp. 286–9). Eastman Kodak’s primary domestic competition after Blair, was DuPont, a chemical manufacturing company looking to diversify its operations after World War I. DuPont began production of motion picture film in 1926, initially in partnership with the distributor Pathé Exchange, and while it is unclear exactly how much of the market share the company claimed, DuPont briefly challenged Eastman’s dominance and spurred a period of rapid innovation in film emulsions (Marzola, 2015: pp. 7–11). The last major nitrate film manufacturer to enter the market was Fuji in Japan, which began production in 1934 (Okada, 2020: p. 283).

Nitrate film ignites easily and burns quickly. It is difficult to extinguish and releases hazardous gasses. Early cinema-related fires – such as those at the Bazar de la Charité Fair in Paris, in May 1897; at a traveling bioscope show in Bilston, Staffordshire, England, in July 1898; and at Salão de Novidades Paris no Rio, the first movie theater in Rio de Janeiro, Brazil, in August 1898 – led to regulations governing the handling, shipment and exhibition of nitrate film. Restrictions and safety measures were especially stringent for film exchanges, where film was stored in large quantities, and theater projection booths, where risk to human life was considered higher (McQueen, 2018: pp. 107–10). Given the risks and regulations, experiments began almost immediately to replace cellulose nitrate with a non-flammable plastic. Cellulose acetate – created by combining cotton cellulose fibers with plasticizers and acetyl acid – was the most viable alternative, and from the 1910s through the 1930s, several different chemical formulas were produced, including cellulose diacetate, cellulose acetate butyrate, and cellulose acetate propionate. Industry personnel, however, consistently found these early acetate stocks to be inferior to nitrate, particularly in terms of tensile strength and toughness. They were also more expensive to manufacture (Smither & Surowiec, 2002: pp. 319–25). So, while acetate stock in a variety of gauges was available from the 1910s onward for amateur filmmaking, non-theatrical exhibitions, and special circumstances like military filmmaking, nitrate remained the professional standard for 35mm theatrical film exhibition until after World War II (Enticknap, 2002: pp. 203–10). 

In 1947, Eastman Kodak released a “high-acetyl” form of cellulose acetate deemed comparable to nitrate on all significant commercial measures, and, in 1950, the company announced that production of nitrate stock had ceased at its Rochester, NY, plant (Fordyce, 1948: pp. 331–50; Enticknap, 2002: pp. 209–10). However, movies continued to be shot on existing nitrate stock, and different countries converted to acetate at differing rates, with the majority phasing-out nitrate between 1950 and 1956. In some countries – including China, the Soviet Union, and Francoist Spain – nitrate film was used for new productions well into the 1960s (FIAF, 1991: p. 20; Bagrov, 2020: p. 287; Peter Bagrov, email to James Layton, May 21, 2024; Arnau & Christensen, 2002: p. 309). 

As nitrate film was phased out of the film industry, it became instead the concern of film archives, and by the 1970s, many repositories viewed it as a burden. First, it poses an obvious fire risk, and numerous institutions – including the National Archives in Suitland, MA, United States; the Cineteca Nacional, in Mexico; and the Cinemateca Brasileira, São Paolo, Brazil – have lost valuable cinematic heritage to nitrate film fires. In addition, cellulose nitrate’s inherent chemical instability causes it to decompose over time. Believing nitrate film would last only 50 years, many archives in the 1970s instituted “copy and destroy” policies, duplicating their nitrate holdings onto acetate and disposing of the originals (Culhane, 1977: pp. 54–5). Unfortunately, cellulose acetate also decomposes over time and ultimately proved less stable than nitrate. Nitrate film will, in fact, last hundreds of years if stored under the proper temperature and relative humidity conditions (Adelstein et al., 2002: pp. 136–43). So, while nitrate film remains subject to safety regulations, including fireproof storage vaults and specialized shipping and disposal, a small number of film heritage institutions, such as the George Eastman Museum in Rochester, New York, have regulation-compliant projection booths that allow original nitrate prints to be screened for twenty-first-century audiences.