Tony White article from http://www.tonywhite.net/process.htm
The Traditional Process of Animation:

The process of animation has changed dramatically over the past ten years or so. Computers, technology and the internet have transformed the world of animated movie making, almost beyond recognition. Now, virtually anyone with a computer, animation software and an attached VCR or CD burner can produce and distribute animated movies independently. But does this personal liberation mean they will actually be "good" animated movies? Animation, at it's very best, is still an exacting process in skill, time and money, although anything which eases the birth process involved has to be embraced with open arms. It must be remembered however that it is not just tools, tricks and ease of opportunity alone that makes for the betterment of animation. It goes without saying that there's no substitute for a good idea... and a well written and recorded script can often override any deficient production values, like an illustrated radio play. However, when it comes down to it, what actually ends up on the screen... i.e. living, breathing characters that are alive with personality... is the one fundamental thing that will separate a great animated movie from a mediocre one. If characters move convincingly... with weight, with attitude, with personality and yes, with "souls"... then the greater battle is won and a fine tradition of animation is upheld and extended. Everything that falls short of this objective however is merely moving drawings.

Whether a project under consideration is for a web site movie, a 30-second commercial, a TV program or a full-length movie... whether it be 2D or 3D, Claymation or Cut-out... the fundamental principles of animated movement will always prevail. For what is true in one aspect of movement is true in all. Naturally, it goes without saying that Web and digitally based animated projects do have far more technical limitations imposed upon them than those of TV or specifically the cinema. However, the essential underlying principles of movement contained within them are the same, whatever their form or length. If there is no "weight" to a character, then that character will fail to convince us that it is as much a living, breathing being as one that does. If a character's dialogue delivery if poor, or out of synch, then a feeling of cheapness and insincerity will prevail. If there is no sense of overlapping action within the movement, then the character will appear wooden and "cut out". Often it doesn't take much extra work to address these deficiencies... but it does require effort, commitment and indeed experience on the part of the animator to implement them economically.

Putting aside for one moment all the wonderful time and cost saving opportunities that the computer age has brought us, it will not be at all detrimental for us to step back for one moment and examine again the production processes that traditional 2D world has evolved in the past to get an animated movie onto the screen. These processes underpin for us just what is still required by the filmmaker in pursuit of a successfully created animated movie. Undoubtedly many of these procedures can be modified and updated to reflect the requirements of contemporary 2D production tools and techniques (and some have already been included below)... in addition to being separately adjusted to serve the differing requirements of the 3D world. As has been stated before, animation is a work intensive operation that requires a disciplined team to keep it's inherent and inevitable time and budget threatening costs under control. The earlier animated filmmakers, through a protracted but tried and tested methods, evolved a successful production system that has served the filmmaking community well for numerous decades. We will deal with this production system in far greater detail later. However, for now, the following brief overview will outline for us the fundament processes involved in producing a successful 2D animated film....

Script. The first, and arguably the most important, stage of any film production is the creation of the script. Indeed, whether it is live action or animation or whatever film genre is under consideration, a "quality" script is fundamental to any project's success or failure. An animated film script differs significantly from a live-action script however. The latter's "dialogue" emphasis is on the whole of more importance than it's descriptive visual action (although in these days of the special effects, virtual reality, adventure story format, this rule is rapidly changing... with live action movies becoming more "cartoon-like" in it's reality bending nature!). Dialogue is less important in animation as it is so much harder to create a convincing, sensitive and expressive performance through an animated character than it is with a real live actor... although the 3D world is actually beginning to come to grips with this problem. Therefore, complicated dialogue and subtle performance would best be avoided if possible, unless the filmmaker is confident that they can overcome the difficulties. Action, plot and visual performance is of course paramount to animation however, as are innovative and imaginative visual ideas. There will always be exceptions to this, of course. The worst possible animated script however... 2D or 3D... is one that is totally devoid of story content and wholly reliant special effects and filmic tricks.

Storyboard: From the formative script stage, the director will supervise the creation of a "storyboard". A storyboard is a series of drawn images that graphically describe the action indicated in the script. Often, in producing a storyboard, deficiencies in the structure and format of the script in question will be recognized and corrected before the time and cost demanding aspects of full production are initiated. The storyboard allows a "think tank" (i.e. the writer, director, producer, and indeed the whole animation team if the project demands it) to view and absorb the action content for possible further comments and improvements. This is at least true on large-scale productions. For short films and commercials however, it is usually the director who draws up their own storyboard.

Soundtrack: After the script and storyboard are approved the "soundtrack" can be produced. The soundtrack is everything audio which underpins the essential animated action of the story. (Note: This is not the overall music "score", which is usually recorded after the film is animated, shot and edited.) Since animation relies fundamentally on a perfect synchronization of the moving picture to the soundtrack, especially "lip sync", an animator needs to have the final soundtrack BEFORE beginning the animation. Indeed, without a final track, the director cannot plan and time out the required scene lengths throughout the movie, or the animator work out his in-scene action timings or "lip sync" from shot to shot. Where the soundtrack is "music" not "dialogue", it is essential to record a basic "guide track" of that music first (if the fully orchestrated piece is not available up front) to indicate the essential "beat" and choreographed "melodies" that are to be animated to. A "click track", which has a predetermined yet regular "click" or "beat' rhythm inlaid into it, ensures that the pace and length of the demo music does not change when the final music is recorded, which would be disastrous if the precisely timed animation is completed prior to the final music record.

Track Breakdown: When the soundtrack has been recorded the sound editor cuts it in accordance with the requirements of the script. This ultimately produces a tightly edited, final track, which cannot be changed once it is established. A "track breakdown" is then produced. Basically, a track breakdown is simply the analyzing the overall timing of a completed track on a frame-by-frame basis, so that scene cuts can be timed out and animation movements co-coordinated with specific words and sound. Such specific points in the soundtrack are identified and located using "feet and frames" reference points. This is especially valuable when analyzing the dialogue sections of the track "phonetically" (i.e. identified by sound rather than by spelling) so the animator can synchronize the drawn mouth positions of a character with the phonetic sounds of the words being spoken or sounds being made. When fully completed, the entire track breakdown for film-based projects is traditionally transferred to a "bar sheet"... a preprinted sheet, designed to allow every frame of soundtrack and film to be identified and analyzed visually. However, with digital production software, such as the universally used and admired "Magpie Pro", the sound breakdown can ultimately be printed out onto standard, letter-format sheets, doing away with the much larger and cumbersome bar sheets traditionally used. One distinct disadvantage of digitally-based track breakdown software however (so far that is...things change so quickly with new technology and it could all be very different in a matter of months!) is the fact that it can only handle "spoken" dialogue tracks and cannot handle instrumentally-based, non-lyric musical material as the traditional film-based approach can.

Designs: While the soundtrack is being broken down (or even long before in some cases) one or more animation designers are assigned to produce the "designs"... complete visual interpretations of all the principal characters featured in the script. (This can be one, or a hundred characters, dependent on the size and scale of the production.) Often at the very beginning of the production's promotion a few key designs would need to have been created, to show potential investors and/or clients just what the final characters will look like. However, once the project gets into full production, these few preliminary character sketches have to be turned into a library of designs, displaying the principal character from every possible angle... as well as creating new characters that have not been designed previously. These design sheets are known as "character model". The more complete and multi-angled the characters are drawn, the easier it will be for the chosen team of animators to maintain a degree of consistency with regards the characters' look. Parallel with the model sheets being created, the background stylist(s) will create various artwork concept designs of each of the key locations found in each principal sequence of the film, for the team of follow-up background artists to work from.

Animatic (Leica Reel): Using the soundtrack, bar sheets and storyboard (and maybe even the "animation layouts", if completed?) an "animatic" of the whole film is created. An animatic is a filmed version of the storyboard edited to the final soundtrack. As a visual dress rehearsal of the final film, the animatic is an ultimate check for the director to ensure that the script, soundtrack, action planning and overall timing of the project is all working as anticipated, prior to the expensive production team of animators, assistants, background artists, etc. are released onto the project in full. Investment in creating an animatic is very wise, as it will avoid huge budget losses further down the road if things do not work out once the animation is completed. (Without an animatic, badly conceived action or timings will not be fully realized until the work is in essence finished... resulting in much of the material having to be redone.) The animatic stage is also the director's final creative "indulgence" stage... where changes and experiments can be made at relatively no cost to the production whatsoever... and modern technology has made this a more and more feasible procedure, more than ever before.

Animation Layouts: For the animator and background artist to know the exact size, position, design and attitude of the characters to be animated, both "character" and "background" layouts have to be produced by a "layout artist". A layout artist has to essentially be a very skilled and versatile artist... in that they also have to accurately sketch out each character and backgrounds in the precise style, size and approach dictated by the initial designs and storyboard. The layout artist also has to "animation aware" enough to understand character action and expression as they additionally have to create sufficient character layout drawings to express to the animator the essential emotion, storyline and character performance intended by the director in each scene. The background artist will also receive a set of identical drawings from the layout artist, so the required scene-by-scene backgrounds can be created to the correct size and in accordance with the animated action.

Pencil Tests. When the animatic is approved and all the animation layouts completed, a team of animators are finally let loose on the production who begin to produce a "pencil test" (also known as a "line test" in Europe) for each scene. Pencil tests are the black line pencil drawings of the animation, shot to the precise timings of the scene, as directed by the track breakdown and animatic. If the initial pencil test shows that the action is not quite working in accordance with the director's wishes, changes can be made and the pencil test re-shot. Ultimately though, the pencil tests will be approved and edited into the animatic master by the editor. (i.e. each pencil test will systematically replace the animatic drawings on a scene-by-scene basis... something like filling in the pieces of a jigsaw puzzle one by one). Gradually, as each scene's pencil test is completed and cut in, the film's action begins to emerge, to which final continuity and timing "tweaks" can be made to each scene's action, if necessary.

Clean-up. On major, large scale productions it is advisable to have a team of "clean-up artists" on staff. The clean-up artist takes all the approved pencil animation drawings and then "cleans them up"... i.e. gives them a tidier and more consistent visual style, reflecting the original designer's approach. (Note: No two animators draw exactly alike so the clean-up artist is provided to make the overall work from animator to animator consistent from the design and drawing point of view.) This naturally takes pressure off the animators so they can concentrate solely on the character's action and performance, rather than a minutia of design details. Of course, animators do have to adhere to basic design proportions of the characters as they go along, but they don't have to fuss over every little "nit pick" that the clean-up artists can pick up more easily. Once the clean-up has been completed, the scene is re-shot and checked for any errors that may have crept in. If all is OK, the filmed clean-up scene then replaces the pencil test version in the master edit and is shown to the director for final approval.

Ink & Paint. Traditionally speaking, when the director finally approves the cleaned-up animation, each animation drawing is transferred to a thin sheet of acetate (a "cel") and is then painted in the colors dictated by the original design. Using new technology however, the drawing is first digitally scanned and then colored electronically within the computer. In the very early days of 2D animation, transferring each of the drawings to cels involved huge teams of steady-handed "tracers", who painstakingly traced each of the animation drawing onto the cels, usually using a brush or pen. In more recent times however, it became possible to easily Photostat a drawing onto the cel... or even, on rare occasions, have the animator draw the animation drawings directly on to cel, cleaned up, with wax based pencils! Today digital software applications, both bitmap and vector, enable this process to occur far quicker and more time efficiently. Nevertheless, whatever way a production is inked and painted, a significant team of individuals are required to work on this frame by frame process... although computers do make it far quicker it must be said.

Backgrounds. While the animation is being drawn, inked and colored, another team of separate artists produces the necessary "backgrounds". A background is essentially everything behind (or sometimes in front of the animation) that does not move. For continuity reasons, each background artist must be skilled and versatile enough to achieve a consistency of color and style, which must remain identical to the original background designer's artistic technique for the film. Backgrounds can be anything from simple plain colors, to intricate and masterly paintings that would proudly adorn any contemporary art gallery. Backgrounds can either be created traditionally... with brushes, paint and paper... or else created "digitally" via a computer program. Additionally, 3D animation productions require that backgrounds are created in three dimensions too... when lighting and camera angles may be implemented, very much as they are in live action films.

Checking. As colored frames and backgrounds are finalized, they are reviewed by a "checker" who makes sure that all the artwork is drawn, inked or scanned and colored correctly... as well as ensuring that the written instructions for the cameraman/compositor are as accurate and complete as possible. It is essential therefore that the checker be a "detail minded" person and one who focused and efficient in their work. Incomplete or incorrect material that slips through to the final stages of any production can result in a significant loss of time and money for the production and therefore anything that ensures this not happening is considered a wise investment.

Final Shoot/Composite. Once the checker is satisfied that all the artwork is correct, the artwork and camera instructions (traditionally called "dope sheets" or "camera sheets") is passed on to the "rostrum cameraman" (traditional, film approach) or the compositor or the visual editor (digital approach) who brings together all the visual elements... principally animation, backgrounds and special effects... combining them into completed scenes.

Dailies/Rushes. (Traditional film-based approach only!) After the final rostrum shoot is completed, the exposed film is sent to the film laboratories for overnight processing. It returns the following morning, ready for projection as "dailies". The dailies are the projected scenes, viewed by the director for final approval. If any errors are found however, here is the time when that problem must be identified and rectified, invariably resulting in the scene being re-shot and viewed again. If, on the other hand, the director is satisfied, the approved rushes are forwarded to the film editor to be cut into the final "answer print" (picture and soundtrack combined).

Final edit. Whether created traditionally or with digital technology, the approved scenes are cut together with the soundtrack for final viewing. (Traditionally called a "double head".) Unlike live action filmmaking, the final edit on an animated film is not particularly "creative"... being that the director made all the essential timing and filmmaking decisions at the animatic stage. The final edit in animation is therefore more of a mechanical process, of dropping completed scenes into the original pencil test/animatic... replacing black and white, pencils drawn scenes with their finished, colored counterparts.

Dubbing. When the whole film exists in a final "double head" form (i.e. the final animation and soundtrack completed and synchronized together) and the director is satisfied with everything, the sound editor at last proceeds to select the sound effects (SFX) required to be heard with the visual action in the film. If these effects cannot be found in existing sound FX libraries, the editor will actually have to record them "live" themselves. Then, once all the sound effects are acquired, one way or another, they are assembled in perfect synchronization with the original soundtrack, and "dubbed". Dubbing is the process whereby the dialogue track, music, and all sound effects are each skillfully mixed into one complete soundtrack. (Although, with internationally targeted TV and theatrical films, the dialogue is usually kept separate from the dubbed "music & effects" track... so that a different foreign language version of the dialogue can be recorded and dubbed to the "M&E" track in the country of screening.)

Answer Print. Traditionally speaking, from the double head, an editor orders an "answer print" from the film laboratories. An answer print involves the combining of the sound and picture into one. As well as an extensive session of "color grading" (checking, scene by scene, that the colors of the picture are accurately and consistently reproduced) the sound is placed onto the film by way of an "optical track". The optical track entails the transfer of all the dubbed audio elements of the magnetic soundtrack into a varying-intensity visual format. The final film will ultimately display a thin, width-changing, transparent strip along one side of the film which, when light is passed through it in the cinematic projector, converts the visual variations into sound variation by the projector's sound system ... reproducing the soundtrack as dubbed originally. Digitally the visual color correction is pre-assigned on the computer and is then rendered, together with the digital soundtrack, onto the final film by way of a specialized, high-powered optical printer.