Lantern slides first originated in the 17th century with use of Magic Lantern projectors. Lantern slides at this time consisted of hand painted images on glass that were projected through light to be used as a tool for storytelling and an “apparatus of magic and spirituality”. It was not until 1849 – ten years after the invention of photography – that photographic glass lantern slides were introduced. William and Frederick Langenheim around the same time were able to develop a method to allow the mass production of photographic lantern slides called the hyalotype lantern slide. Hyalotypes were created using one of two methods: Contact or Reduction prints. The introduction of the hyalotype print allowed manufacturers to produce slides in a more efficient and cheaper way. As a result, lantern slides became a tool for education, scientific study, travelogues and more. Even though this technology was introduced in 1849, it did not reach its peak popularity until the early 20th century.
A lantern slide is a positive image showcased on a piece of glass. Through the contact or reduction process, a hyalotype slide is produced on the glass, which is then masked with black paper around the edges. Then a second piece of glass covers the photograph and its masked edges to protect the image. Finally, gummed paper is used to hold the image’s glass edges together. The slide’s paper border was often labelled with a caption or description of the image as well as the studio or company that produced it. The European standard size for slides was 3.5 x 3.5 inches and the French standard size was 3.25 x 4 inches.
The photographs pictured on lantern slides appeared in black and white, and if colour was desired the slides would have to be hand painted, often times by women. This task required special skill and usually slowed down production. Paints such as transparent oil paints, aniline dyes, and watercolours were used, but by the 20th century paints specifically for lantern slides were produced.
 Cox, Amy. “Purifying Bodies, Translating Race: The Lantern Slides of Sir Everard im Thurn.” History of Photography no. 4, vol. 31 (Jan. 2008): 350. http://www.tandfonline.com.proxy.library.carleton.ca/doi/10.1080/030872907016058
 Worth, Tim W., “Cool Things in the Collection: Reverend Salton’s Magic Lantern,” Manitoba History no.83 (Spring 2017): 48. https://search-proquest-com.proxy.library.carleton.ca/docview/1931580026...
 “About Lantern Slides,” para 4, University of South Florida Libraries, Sept. 28, 2017. http://www.lib.usf.edu/special-collections/arts/about-lantern-slides/
 Ibid. Para 4.