Please Stay By My Side,
In My Dreams...

Animation Production Art Terminology

Settei Sets - Model Sheets

Color Test/Model Cels

Concept Art

Settei sets are drawn by the Character Designer to make sure that all the moving parts in animation the in-betweeners, animators, and directors all keep the characters looking uniform, or as animators will say on model.  When someone is talking about how some animation is off model this is what they are talking about; the animation does not match what the character designer intended.  A note on finding these you will mostly find these in photocopy format, and occasionally the hand drawn sets will come up, these are generally rare and super expensive.
This type of Art is used during the pre-production phase, generally when the production committee is getting together to decide whether to greenlight a project.  It can include: proposals, cels, sketches, and even painted art.  Disney has been known to use sculpture as well.  The medium used will depend on what the artists are comfortable with and the requirements of the committee.  Art from this category is generally VERY hard to find.
These are generally a very simple cel of just a character to show what colors should be used by the painters when they are painting the cels.  Model/Color Test Cels are very specific to pre 2001 animation, as with the modern Settei sheets will come with something called a color reference that basically does the same thing but is in reference to the colors painted in digitally.  Their rarity depends on the series for this, there seem to be a lot of test cels from both CCS and x/1999 that I have seen.

Storyboard

Original Layout

Copy Layout

Storyboards are not exclusive to animation. Live action TV and movies will sometimes use them to diagram a shot.  The Storyboard is a tool that the episode and animation directors will use to maintain the overall look of what was decided when putting the episode together.
Original Layouts are the pencil sketches that layout the cut in deference to the storyboard they are a reference for both the key animator and the BG artist.  There are two roles that will work on Original Layouts, it could be the Key Animator of the cut or it could be an actual Layout Artist, for some of the bigger productions studios will hire an artist that specifically specializes in Layouts it doesn't happen a lot, but sometimes it does. Original layouts you will find come with BGs and sketches.
It is what it sounds like, it is a photocopy of the original Layout this happens on every cut that is animated the original Layout will either go to the Key Animator or the BG Artist, or vice versa.  This is to keep both sides of the animation on point.  While some BGs are digitally rendered usually when a studio wants to create a cool camera movement.  MOST BGs are still hand painted and scanned in.  Copy layouts you will find come with BGs and sketches.

Background

Rough Genga

Genga

Backgrounds are usually drawn and painted with watercolor or gouache paint.  Acrylic is not normally used for backgrounds because it has a nasty habit of sticking to itself and thus might damage the painted cels.  Backgrounds are also a specialized field of animation. They require a lot of talent and a good understanding of blocking.  You can find Backgrounds for shows all the way up to the present day and, while they can be pricey, they generally will not cost as much as you would think.
Rough gengas are usually a precursor to the next step they can be detailed bet generally they are VERY rough and in some cases almost stick figures to help plan out the movement of the character (s)  in the sequence.  Most times these sketches are not numbered at all or misnumbered... numbering most times is worked out in the next step.
The genga step takes the rough movements and polishes them into more detailed sketches these are drawn and redrawn again and again as needed, at this step the Key animator will work closely with the animation director to get the exact key points in the movement correctly.  Genga are easy to identify in that they are usually numbered in the middle of the page with a circle around them.  And pencil colors are usually numerous in Gengas, especially with the new computer animated shows.

Shuusei

Douga

In-Betweens

A Shuusei is another word for a correction, a shuusei is drawn by the Animation Director of the episode and sometimes if you are lucky you will find one done by the Chief Animationn Director...  It depends on how hands on both directors are and how important the image is for a full correction.  A lot if shuusei are partials of a hand or small detail that needs fixing.  Shuusei are drawn on a rainbow of colored paper, and generally will have a higher quality than the other sketches in the set.
A douga is the clean up sketch, basically the gengas are sent to the douga-men, to be cleaned up and basically retraced on clean white paper with the sketch number moved to the top right corner.  These sketches are what finally makes it to the screen, if it is a computer animated show the sketches are scanned and then digitally colorized if we are talking a show pre-2001 they are then made into Cels.
 
The cleaned dougas are then sent to the in-betweeners to animate the weird in between pieces that are between key cels/sketches.  Some are great looking others can just be awkward because they were never meant to be seen!  The way to identify an in-between is the number will be something like A2 with no circle, triangle, box, or dash around the number.  A notation around the number would mean it is a key cel.

Cel

A cel is made from the photocopies of the dougas onto a clear sheet of acetate and then painted to match the color key for the character (s).   They are the finished product of the animation process.  Most cels are farmed out to offshore studios that churn them out in bulk leading to mistakes, every cel that goes under the camera, must be checked by someone, as crazy things can happen leading to entire cuts getting reanimated, paint, weird coloring, and disappearing objects from frame to frame.