What are transparent sheets of film on which objects are drawn or painted for traditional hand-drawn animation?

Sometimes referred to as cel animation -cel is short for celluloid which is a transparent sheet on which objects are drawn-, traditional animation is a technique where each frame is drawn by hand. It’s also called classical or hand-drawn animation.

Fantasmagorie is the first animated film in history created using traditional animation by The French caricaturist Émile Cohl in 1908.

You can watch it here:

The film mainly consists of a stick man, drawn in chalk-line style by the artist’s hand on camera, moving around and interacting with different morphing objects. It might have lacked a solid storyline, but it introduced enough creativity to show what animation could accomplish.

Traditional animation techniques

The traditional approach is very fascinating for pencil lovers. The animation is drawn by hand for every frame, and each drawing is a little bit different from the previous one.

All the drawings are fed into plastic cells, filled with paint in the desired colors, and are then photographed one-by-one into an animated sequence on a painted background image.

The animator draws some frames on cellulose sheets designed for drawing, then these cels are laid over other ones to be photographed. This allows the animator to reuse the drawings without having to fully re-draw components for each frame.

Computers now facilitate this animation process, making the traditional cel drawing process nearly obsolete by the beginning of the 21st century.

Special computer software has made it possible for drawings to be directly drawn or scanned into the computer system. Followed by digitally colorizing these drawings and also simulating camera work, then finally processing the output to allow the film to be exported in different formats, like the old 35mm film or digital video.

Computers have also lowered the costs of the animation process by eliminating the need for materials like acetate sheets and inks. The traditional process used to be expensive and time consuming, requiring lots of money to be spent on materials and human labor depending on how many cells and backgrounds need to be created.

Traditional animation process

Storyboards

The storyboarding process was originally developed at Walt Disney Productions in the early 1930s, and it’s usually the first step in making traditional animation. A storyboard is a collection of hand drawings and words that tell a story, similar to large comic strips. The drawings are displayed in a certain sequence, so the viewer can pre-visualize the animation.

This process is often repeated many times before reaching the final desired outcome. It helps the animators to set plans for the animation plot and defines the composition of the imagery.

Voice recording

A preparatory soundtrack is often recorded before true animation begins, so that the animation can more accurately synchronized to the soundtrack. This is due to the slow systematic way in which traditional animation is produced, so it’s almost always easier to synchronize the animation to an existing soundtrack, than it is to synchronize a soundtrack to an existing animation.

A full soundtrack will contain music, sound effects, and dialogue performed by voice actors. The scratch track used during animation, however, normally contains just the voices, the vocal songs to which characters sing along, and some temporary musical score tracks, with the final score and sound effects added during post-production.

After the soundtrack is created, an animatic or a story reel is made to determine the overall effectiveness of the animation before finalizing things. An animatic is usually a sequence of images or sketches, in the form of a storyboard, arranged with a soundtrack, and produced right before the full animation begins.

This stage helps animators and directors to identify any script or timing issues that could exist with the produced storyboard and fix them as needed. This process could result in creating new versions of either the storyboard or the soundtrack, or both, and creating a new animatic for review until everything is perfected to the desired extent. This could prevent animating scenes that could be edited out of the film, avoiding a potential loss in time and money.

Design and timing

When the animators and the directors decide on a certain animatic, they send it along with the approved storyboards to the design department, so character designers can prepare model sheets for different characters and objects in the animation.

These model sheets show the designers how every character or object looks from different angles with a variety of poses and expressions, so that all artists working on the project can deliver the same output.

It’s necessary sometimes to see how certain characters look like in three dimensions to get a better understanding of a character’s design. That’s when macquettes are produced, they are small statues that depict a character in the 3D space.

Meanwhile, the background and color stylists and art directors will do similar work to setup the locations, determine the art style and color schemes to be used in the project.

At the same time, the timing director, who is usually the main director, takes the final animatic and analyzes what poses, drawings, and lip movements will be needed on what frames. He creates what’s called an exposure sheet, which is a printed table that breaks down the action, dialogue, and sound frame-by-frame as a guide for the animators.

If a film relies heavily on music, a bar sheet may be prepared in addition to or instead of an X-sheet. Bar sheets show the relationship between the on-screen action, the dialogue, and the actual musical notation used in the score.

Layout

After the designs are finished and approved by the director, they layout process comes in action. The layout artists determine the camera angles and lighting of the scene, along with the main poses for characters.

The layout, storyboards and the audio are finally joined together to form a more final animatic.

Animation

The animation stage finally begins after the animatic is approved by the director. The traditional animation process begins by drawing a sequence of animation on sheets of transparent paper with holes in it to fit the peg bars in their desks, usually using colored pencils, one picture or “frame” at a time. A peg bar is an animation tool that is used in traditional animation to keep the drawings in place. It contains pins that match the holes in the paper. It is attached to the animation desk or light table, whichever is being used.

Using the character layouts as a guide, a lead or key animator will draw the key drawings in a scene. He draws the necessary frames to define the major points of the action. 

For example, for character jumping across a gap, he may draw the frame where the character is about to leap, a couple of frames as the character is flying mid-air, and the frame where the character lands on the other side of the gap.

A pencil test, where pencil drawings are scanned and synced with audio, is usually prepared before the final version of the animated scene. These pencil tests can be made nowadays using computer software and a video camera. This allows the animation to be further reviewed and improved before adding details and some of the missing frames.

The final result is tested and corrected until the lead animator is ready to meet with the director and have his scene sweatboxed, or reviewed by the director, producer, and other key team members. Sweatboxing is the process of reviewing the animation as it developed. Similar to the storyboarding stage, an animator may need to re-do a scene multiple times before the director will approve it in the scene.

Timing is crucial for the animators drawing these frames; each frame must exactly match what is happening on in the soundtrack once the frame appears, or else visuals and sound will be out of synchronization, which will distract or confuse the audience. For example, in high-budget productions, lots of effort is given in making sure a speaking character’s mouth movement matches in shape the sound that character’s actor is producing as the character speaks.

When the key animation is approved, it’s forwarded to the clean-up department where the drawings are traced onto a new sheet of paper, taking care in including all the details on the original model sheets, so that it appears that one person animated the entire film. Then any missing frames between the key frames are drawn in a process called tweening. The resulting drawings are again pencil-tested and sweatboxed until they are finally approved.

Approved artwork is always spliced into the Leica reel is a type of storyboarding device. Unlike actual storyboards or pitches, Leica reels are used later in the development process, usually after voice has been recorded, and are not used for selling or marketing the project.

This process goes for both character and special effects animation, which are done in separate departments in high-budget production. Effects animators work with anything that moves and is not a character, including props, vehicles, machinery and particles such as fire, rain, and explosions. Sometimes a number of special processes are needed to produce special effects in animated films; rain, for example, has been created in Disney animated films since the late-1930s by filming slow-motion footage of water over a black background.

Backgrounds

The background artists usually work on painting the settings over which the animation takes place. The backgrounds are mostly done in gouache or acrylic paint, but some animations have used watercolor or oil paint backgrounds.

Background artists follow very closely the work of the background layout artists and color stylists, so that the resulting backgrounds are in harmony with the character designs.

Traditional ink-and-paint and camera

After the clean-up and tweening processes for a sequence are completed, they are prepared for photography, a process known as ink-and-paint.

The outline of the drawing is inked or photocopied onto the cel, and gouache, acrylic or a similar type of paint is used on the reverse sides of the cels to add colors in the appropriate shades.

Characters will mostly have more than one color palette assigned to them; so each one can be used depending on the mood and lighting of the scene. Cels being transparent by nature, allow for each character or object in a frame to be animated on different cels, as the cel of one character can be seen underneath the cel of another; and the blurry background will be seen beneath all the cels.

The photography process begins once a full animation sequence has been transferred to cels, with each cel laid on top of each other, and the background sitting at the bottom.

A composite image is prepared for photography by lowering a piece of glass onto the artwork to flatten any irregularities, then shooting the image with a special animation camera called rostrum camera. The cels are then removed, and the process is repeated for the next frame until all frames in the sequence have been photographed.

To avoid producing an animation that is jittery, each cel is fixed on peg bars before the camera, to make sure that each cel aligns wit hthe one before it.

Sometimes, the process of photography may need to be repeated for certain frames, to implement some needed camera effects like superimposition or panning. Superimposition means placing image or video over another existing image or video. Panning is created by either moving the cels or backgrounds one step at a time, over a series of frames.

Among the most common types of animation rostrum cameras was the Oxberry. Such cameras were always made of black anodized aluminum, and commonly had 2 pegbars, one at the top and one at the bottom of the lightbox. The Oxberry Master Series had four pegbars, two above and two below, and sometimes used a “floating pegbar” as well. The height of the column on which the camera was mounted determined the amount of zoom achievable on a piece of artwork. Such cameras were massive mechanical affairs which might weigh close to a ton and take hours to break down or set up.

In the later years of the animation rostrum camera, stepper motors controlled by computers were attached to the various axes of movement of the camera, thus saving many hours of hand cranking by human operators. A notable early use of computer cameras was in Star Wars (1977), using the Dykstra system at Lucas’ Sun Valley facility. Gradually, motion control techniques were adopted throughout the industry. While several computer camera software packages became available in the early 1980s, the Tondreau System became one of the most widely adopted.

As the scenes come out of final photography, they are spliced into the Leica reel, replacing pencil animations. Once every sequence in the production has been photographed, the final film is sent for development and processing, while the final music and sound effects are added to the soundtrack. Again, editing in the traditional live-action sense is generally not done in animation, but if it is required it is done at this time, before the final print of the film is ready for duplication or broadcast.

Digital ink and paint processes gradually made these traditional animation techniques and equipment obsolete.

Digital ink and paint

The current process, termed “digital ink and paint”, is the same as traditional ink and paint. With the main difference being scanning the drawings and the backgrounds after they’re completed into a computer, instead of transferring them to cels. They can even directly on the computer monitor, and have their colors added and processed using specialized computer software.

The digital drawings are then composited over their respective backgrounds, unless they were also digitally painted, and the computer finally outputs the film by either exporting it as a digital video file, using a video cassette recorder, or printing to film using high-resolution output device.

Computers and the internet have generally made it easier to exchange artwork between different departments or studios, and even across distant countries and continents. Disney’s animation studio was the first to implement digital ink-and-paint process, while many filmmakers didn’t want to go digital, because they felt that two-dimensional animation has lost the natural and aesthetic appeal of the craft.

Many animated cartoon series at the time were still animated in foreign countries by using the traditionally inked-and-painted cel process as late as 2004; though most of them switched over to the digital process at some point during their run. For example, Hey Arnold! and SpongeBob SquarePants made the switch in 1999 and 2000, respectively. Other shows, such as The Powerpuff Girls, The Simpsons, and King of the Hill, tested the digital ink process for a few episodes but didn’t fully upgrade until later on. Finally, Ed, Edd n Eddy aired its last cel episode in 2004, and then came back in digital ink and paint, even though new shows using the digital inking and painting process, like Futurama and Family Guy (both of which premiered in 1999), were first appearing.

Computers and digital video cameras

Computers and digital video cameras can also be used as tools to assist in traditional cel animation without affecting the film directly, helping the animators in their work and making the whole process a lot faster and easier. For example, doing the layouts on a computer is much more effective than doing it by traditional methods. Additionally, video cameras give the opportunity to see a “preview” of the scenes and how they will look when finished, enabling the animators to correct and improve upon them without having to complete them first. This can be considered a digital form of pencil testing.

Examples of Traditional Animation Films:
  • Snow White and the Seven Dwarfs (1937)
  • Pinocchio (1940)
  • Fantasia (1940)

As traditional, hand-drawn animation is greatly influenced by the skill and artistic style of the animators producing the frames, the terms full and limited animation were coined to describe the quality of the animations produced: -

  • Full animation is the one having all its drawings distinctly different with no repeating images. This term is used to describe the process of producing high quality hand-drawn animations that contain detailed drawings and realistic movements.
  • Many of the Disney animated films are clear examples of full animation, as opposed to the more cartoon styles of the Warner Bros. animation studio.
  • Limited animation on the other hand, is the animation that uses less detailed drawings, and fewer methods of movement. It usually contains more camera movement to make the animation seem more dynamic even if the movements created weren’t very fluid. Limited animation usually has most of its focus placed on the sound with voice over, narration and dialogue, as opposed to full animation that focuses more on the visuals.
  • In the 1940’s, several animators who left Disney formed the United Productions of America. In response to the overly naturalistic practices of Disney animation, these artists pioneered the aesthetic technique of limited animation—creating a flat and planar world to react against the world of Disney cartoon space. Limited animation is primarily used in the production of cost-effective material for television (such as the work of Hanna-Barbera, Filmation, or web cartoons) where a large output of animations is required.