During the making of 'Snow White and the Seven Dwarfs', Walt Disney realised that the studio at Hyperion Avenue was grossly understaffed to pull off the ambitious project. Walt turned to art instructor Don Graham, a Canadian-American fine artist who had been the head of internal training at the studio since 1932. He told Graham he needed 300 new artists, right now, and that it was Graham’s job to find the right candidates. In a long memo to Graham in 1935, Walt outlined the qualities he believed were essential for a good animator:

• Good draftsmanship
• Knowledge of caricature, of action as well as features
• Knowledge and appreciation of acting
• Ability to think up gags and put over gags
• Knowledge of story construction and audience values
• Knowledge and understanding of all the mechanical and detailed routine involved in his work, in order that he may be able to apply his other abilities without becoming tied in a knot by lack of technique along these lines

Drawing is giving a performance; an artist is an actor who is not limited by his body, only by his ability and, perhaps, experience.

In the 1920s, the defining animation style was "rubber hose", where limbs and bodies moved in a free-flowing manner without articulation. This style meant that the animation did not need to adhere to laws of gravity or anatomy, and that the physical form and volume of the characters could be freely manipulated. Much of the work in the "rubber hose" period was led by gags rather than character or narrative.

In the lead-up to 'Snow White and the Seven Dwarfs', Walt began pushing for the opposite, for gags and situations to arise out of the story and the characters themselves. He also demanded that his animators begin a classical arts training to better understand form and anatomy, beginning a push towards greater realism in animation. This also included secondary actions, including the follow-through movement of clothes, hair and even skin. The animators were now not just cartoonists but actors themselves, just as concerned with the inner life of the characters as they were with their physical form.

"You have to portray not only (that) this thing is moving”, he said in 1942, “but it is actually alive and thinks.” His philosophies would completely shift the principles of animation and establish his studio as the highwater mark for animation for decades to come.

Does your drawing have weight, depth and balance?

1. Story and Storyboarding

Walt Disney, the sequence directors and the animation staff gather for story meetings, where the narrative is plotted, gags are woven in and the film itself is storyboarded out as reference for the sequence directors and composers. They first began using this process with 'Three Little Pigs' (1933), after which it became standard practice for animated films to this day. Once storyboards are completed, they are filmed for a Leica Reel, temp dialogue is recorded and the reel reviewed in sweatbox sessions until the story is agreed upon.

2. Sequence and Timing

For each "scene", the sequence director, the composer and the layout artist use a stopwatch, a metronome and a piano to map the specific timings of every moment. This would include what movements occurred on which beat, where the action would take place and how much time was required for each action to be effectively animated. Everything was then broken down into units on an exposure sheet to ensure it would all fit within the 24-frames-per-second, 16-frames-per-foot parameters.

3. Animation

You do not make drawings just because they are cute or look funny. You make drawings that will stage each idea in the strongest and simplest way before going on to the next action. You are saying in effect, 'Look at this - now look at this - and now this.'

Before beginning work, the animator assigned to a scene and the supervising director have a handout session, where the director explains the context of the scene. The animators begin with thumbnail sketches to chart out initial ideas.

Using the exposure sheet, the lead animators sketches the key frames of the action, working from the breakdown of what action each frame required. Lead animators focus on a particular scene, character or set of characters. In-between animators then fill in the action between the key frames.

The process begins with rough animation, which is then shown during sweatbox sessions to the supervising directors and Walt for approval. Once final approval is given, the animation is cleaned-up and refined by a clean-up team of animation assistants before moving to the inking stage.

Hundreds of thousands of drawings were created in this stage. For example, 'Snow White' required over 200,000 separate drawings.

You must exaggerate a character very much. We want to make things more interesting than in ordinary life... Our actors must be more unusual and more interesting than you or me.

4. Inking and Painting

The women in Inking and Painting then transfer the pencil animation with ink onto transparent cels. Paint is then added on the opposite side of the cel to preserve the integrity of the lines. At the studio, Walt preferred shaded lines, which were harder to achieve.

5. Backgrounds

While the animation work is happening, the background artwork is completed, often using watercolours, oil paint or gouache on paper or canvas. They are designed to offer a sense of perspective and to facilitate the action of the animation. In the case of a multiplane shot, many different layers, including foreground, are painted on glass panes.

6. Camera

The animation cels are then photographed along with the background artwork, either with a traditional animation camera set-up (animation cels pegged down and photographed as still images) or with the multiplane camera. Each individual cel is photographed, culminating in the 24 frames required for each second. If the cels sustained any smudging or damage in this process, the cel would be returned to Inking and Painting for clean-up. Special effects would also be added at this point.

In our minds, as we were working on the pictures at the studio, I do not believe there was much thought given to the music as one thing and the animation as another. I believe we conceived of them as elements which we were trying to fuse into a whole new thing that would be more than simply movement plus sound. It was always a team effort, a pooling of talents of all into what anyone was doing.

• The Disney Studio Story, Richard Hollis and Brian Sibley, 1988
• Disney Animation: The Illusion of Life (Popular Edition), Frank Thomas and Ollie Johnston, 1984
• The Archive Series: Nine Old Men - The Flipbooks, Pete Doctor, 2012
• Walt Disney: The Triumph of the American Imagination, Neal Gabler, 2006