When was the film released?

After gelatin dry printing is widely used, the exploration of improving photosensitive materials continues. People found that the gelatin dry plate based on glass was fragile and bulky, so they began to look for a material that was lighter and easier to bend than glass plate as the substrate.

1887, Hannibal Goodwin (1822 ~1900), an American priest and photographer, spent ten years successfully coating photographic emulsion on celluloid (a nitrocellulose plastic) sheet, thus making the glass-based dry plate easy to carry.

At the same time, george eastman, the founder of Hysmans Dry Board Company, is also improving the glass substrate. 1888, Heismann Dry Plate Company produced the earliest film based on white paper. This paper film is called "American film" and can shoot 100 circular negatives with a diameter of 6 cm. After the film is developed, the emulsion should be peeled off from the paper base and sandwiched in glass to print the photos. Because of the complicated process, it is difficult for photographers to handle it themselves, and they must be sent back to Hysmans Dry Plate Company for processing. At the same time, the film based on white paper strip has an obvious defect. When printing, paper particles are easy to appear in photos.

1889, Heismann Dry Film Company was renamed Kodak Dry Film Company, and celluloid was used as the film base to mass-produce films. This celluloid-based film quickly swept the world. 10 years later, about 80% of the film in the world was produced by Kodak.

Using celluloid as film base still has many disadvantages, especially nitrocellulose, which is easy to burn and has certain danger. 1930, people switched to cellulose acetate as the membrane base. Cellulose acetate is not easy to burn, so it is called "safety film base" and is still in use today.