The development of cel animation greatly simplified the animator's task. Working on transparent celluloid or acetate sheets called "cels" freed the animator from repeatedly drawing the same image and made it unnecessary to redraw background images. Separate elements of the drawing could be placed on individual cels and then assembled in layers of two or three for the camera. For example, if one scene showed only a moving arm, the animator might draw the body on one cel and each progressive arm movement on additional cels. Then the various movements could be inserted on the same body visual in subsequent scenes. Cels also enabled the animator to include more detail in the characters and background, as one drawing could be used multiple times without recopying.

Part A
As animated films have become longer and more elaborate, an assembly line of sorts has developed in the studios. Certain animators specialize in backgrounds, while others design and draw the extremes. "In-betweeners" then complete the numerous drawings that connect the two extremes. Other animators fill in the colors, clean up the drawings, and apply special effects such as fire, smoke, water, shadows and lighting.

The boxes on the activity sheet represent frames in an animated film. In the first row, the beginning and ending "extremes" of an action are shown. It takes planning to get to the right position at the right time. Thought, as well as imagination, is required to make something move in a believable way. To illustrate the process, have your students use the middle five boxes on that page to take the action from its beginning to its end. Check that the midpoint of the movement occurs in the middle box.

First box	Middle box	Final box

Next, in the second row, have your students complete the action shown in the first two boxes. Ask them to consider different ways of visualizing movement. For example, they might act out a possible sequence, or they might observe a similar action in real life. Have them change one element of the series and discuss how that change affects the outcome or the mood. Then have them add a special effect.

First box	Second box

Supplementary Activity:
Have your students analyze the scene they have just drawn to determine how many different cels would be needed to film it. These might include a background cel, cels for the changing positions of the characters or objects, and a cel for a special effect such as weather, shadows or reflections. Ask them to consider what cels would have to be added or changed for the actions to take place and what cels would remain the same throughout the scene. Then have them make cels on sheets of acetate or tracing paper and experiment with exchanging them to create new scenes.

Part B
Like painters, animators use perspective and scale to create depth, and color to enhance mood, but most of the visual information in an animated film is transmitted through movement. Before animating a scene, animators study the way their subjects move, whether they are animals, people or leafy trees. Although the movements they draw are based on real life, animators often caricature or exaggerate both movement and design. Animated characters, like human actors, express themselves with gestures, mannerisms, posture and facial expressions as well as voice. A tilted head can indicate surprise. A body slanted forward suggests speed. A character freezes at a scary sound. Background movement also conveys meaning. The gentle flutter of leaves signals a breeze, but when the leaves toss and turn, it could mean a storm is coming.

Animators use the term "squash and stretch" to describe the effect of gravity on living creatures and pliable material. Racing after the Road Runner, Wile E. Coyote flies off a cliff and plummets downward. His body smashes into the ground (squash) and then elongates into a bounce (stretch). In this instance, the deformation is used for comic effect, but in more realistic situations squash and stretch lend weight to characters and make expressions such as smiles or frowns convincing.

Choosing the right look for a character is important for creating its personality. A "cute" character might be drawn with characteristics that resemble a human baby's, such as a large head, small body, high forehead, big eyes and short, plump arms and legs. A bully, on the other hand, might have a small head, a thick or nonexistent neck, a big chest, and short legs. Exaggerated features and a quirky posture could indicate a comic character. The animator can also use these traits to ridicule stereotypes. The mutant toys in Toy Story, for example, turn out to be selfless and helpful, not dangerous as they first seem to be. Handsome Gaston in Beauty and the Beast is also egotistical and mean.

Discuss with your students what animator Norman McClaren meant by the statement, “Animation is not the art of drawings-that-move but rather the art of movements-that-are-drawn.” Have them think of an emotion such as anger, fear, happiness or surprise and act it out in front of a mirror or the class. Ask them to describe the facial and body movements that communicated the emotion and explain why some people consider an animator the actor of an animated film.

Supplementary Activity:
Show your students an animated sequence and ask them to describe the characters' personalities and list the ways in which they are revealed. Some suggestions are: the opening sequence of Spirited Away, the scene in which the chickens plot their escape in Chicken Run, and the short Luxo Jr. You might also have your students compare the enchanted objects in Beauty and the Beast with their human manifestations. How do the animators give the same personality to each?