Say you're crazy enough to make a film using drawn -on paper -animation.
The standard process is to do layout drawings which lead to "extreme" drawings. These extremes can be anywhere from 1 to 6 or more drawings apart (3 "in betweens" is typical) and they're the most important drawings for animating character. If the extremes work, the inbetweens will (generally) work.
If you're going to test the animation, this is the best time to do it -before doing dozens of inbetweens.
After you scan, your folder will look like this:
This is based on this pencil test post last week.
These drawings will be timed out an exposure sheet which dictates what drawings are used on what frame.
You'll want to retain your After Effects project for use as the animation progresses and not have to re-expose the artwork. This is time consuming and can be prone to mistakes.
Here's the dumb way to deal with that:
Now you have a numbered sequence which will be identical to the numbered sequence of final drawings.
Import this folder as a sequence into After Effects. Be sure to interpret the footage correctly -we tend to do drawn animation at 24fps (fewer drawings/easier to time), so the footage should import at 24.
Drag it into your timeline and "Time Remap".
Set the key frames to hold and then expose the drawing to the frame. The number in blue to the left will be the same number as your drawing -provided you've got a sequence of consecutive whole numbers starting from 1. The timeline frame count can be set to match your dial number.
Got through and expose the keyframes.
This will give you a properly timed out test.
Once the inbetweens are complete, just replace the files and your exposure will remain.
This is the simplest way of keeping the process streamlined.