Published: April 7, 2025 | Last Updated: April 11, 2025
Featured image: Inking and painting an animation cel, 1969. Image Credit: Janke at English Wikipedia, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons
CEL ANIMATION DEFINITION & MEANING
Cel animation is a traditional 2D animation technique where characters and objects are drawn on transparent sheets called cels, then layered over painted backgrounds and photographed one frame at a time. It was the dominant animation method for most of the 20th century before being replaced by digital tools.
How cel animation works
Each cel is a transparent sheet—originally made of celluloid, later cellulose acetate, and eventually polyester. The animator draws the character’s outline on the front of the cel, then paints the colors on the back to avoid smudging the ink. Backgrounds are painted separately and reused across multiple frames.
Here’s a behind-the-scenes explanation about how it is still done:
The finished cel is placed over the background and photographed with a rostrum camera:
This process repeats for every frame of the scene. Most animations were shot at 24 frames per second, but often animated on twos—meaning one drawing is shown for two frames, cutting the drawing load in half.
Why cel animation became the standard
Cel animation solved the efficiency problem of redrawing every detail for every frame. Since backgrounds didn’t need to move most of the time, they could be static paintings, while only characters or moving elements were animated on cels. This allowed studios to streamline production.
Disney, Warner Bros., and Fleischer Studios refined the technique during the 1930s–1960s, turning it into a full-blown industry pipeline. Cells’ clarity, color fidelity, and layering precision were ideal for theatrical-quality animation.
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Materials and preservation
The original material, cellulose nitrate, was flammable and unstable. It yellowed, warped, and deteriorated over time. Later, acetate replaced it—but even that was prone to “vinegar syndrome,” releasing acidic fumes as it aged. Only polyester proved stable long-term, but cel animation was already fading out by the time it was introduced.
Today, original cels are rare collectibles. Their fragility makes preservation difficult, and many were discarded once scenes were completed. Studios like Disney only began archiving cels in the 1980s, recognizing their value as part of animation history.
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Cel animation vs digital workflows
The early 1990s nearly phased out cel animation. Oliver & Company (1988) was the last fully cel-animated Disney feature. The Little Mermaid (1989) still used cels but included early digital processes. From Beauty and the Beast (1991) onward, digital ink-and-paint software replaced the physical cel pipeline.
Today, even hand-drawn animations are usually drawn on tablets and colored digitally. Tools like Toon Boom Harmony and TVPaint simulate the cel workflow, without the physical layers. This speeds up production and allows instant corrections, layering, and color testing.
See also a complete overview of the history of film and animation.
Why cel animation still matters
Cel animation isn’t just a technique—it’s a visual language built on labor, timing, and tactile process. Each frame was a physical object, and every moment of motion was drawn by hand. That level of detail and imperfection created a unique aesthetic that digital tools still struggle to authentically.
Filmmakers like Don Hertzfeldt and studios like Studio Ghibli continue to draw influence from cel methods. While digital workflows are common in anime, many artists still simulate cel-era texture through frame economy and color layering.
Summing up
Cel animation is the foundation of traditional 2D animation. For decades of classic films, it combined hand-drawn movement with painted backgrounds, frame by frame.
Though rarely used in commercial production today, the technique shaped the visual grammar of animation and continues to influence how stories are drawn, timed, and felt.
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