Invention of the cel technique stretches back to 1914, when an employee of the John Bray Studio named Earl Hurd first perfected it. He patented the process himself, but lent the studio the rights to use the patent. They collected royalties from other studios and reaped a windfall on Hurd’s hard work. The patent expired in 1932, allowing anyone to use the technique.
Before the 1950s, animation cels were inked and colored by hand. The Walt Disney Studios changed that with the application of the xerography technique--the process of copying words and drawings on paper (as in “Xeroxing”). Xerography was invented by Chester Carlson in 1938, but the Disney Studios first applied it to the animated cel. It allowed them to transfer ink sketches onto the cels very quickly, sparing time and expense. Disney used xerography sparingly in the 1959 feature film “Sleeping Beauty,” then applied it wholesale for 1961’s “101 Dalmations.”
Disney scored a further technical advancement in cel technology in 1985, when Dave Spencer perfected the Animation Photo Transfer (APT) process. Artists would paint an image that could then be transferred wholesale onto the cel through a photo-negative process. (Basically, the cel acted as the material for the photograph.) Chemicals could then remove the ink from the non-exposed areas. As with most cel animation developments, it saved a great deal of time and work hours. Disney first applied the process to its 1985 film “The Black Cauldron.”
The advent of computer animation sounded the death knell for cels. The Computer Animation Production System (CAPS) replaced cels with a series of software programs and camera systems that allowed animators to duplicate the effects of cels digitally. Cels were delicate and flammable, so CAPS meant that studios could store completed animation much more securely. Disney first used the CAPS process for the end of 1989’s “The Little Mermaid,” then for the entirety of 1990’s “The Rescuers Down Under.” It constituted the end of cel animation as we know it.
Though now defunct, many completed animation cels are valuable collector’s items. The process of rendering the artwork by hand onto the cels made them desirable pieces of art. Particularly valuable cels can go for thousands of dollars. Sotheby’s sold one from the movie “Who Framed Roger Rabbit?” for over $50,000 in 1989.