If you like the world of motion graphics, you may remember that scene from childhood where you used to draw a few pictures on the edge of the pages of a notebook to see if you could replicate a classic and vintage animation effect.

That process of drawing something on a single sheet of paper and adding changes and details on forwarding sheets to create the sense of movement of a scene is known as frame-by-frame animation. To recreate that technique correctly digitally, you must activate specific options. So here's how to set up a composition for frame-by-frame animation in After Effects.

Using the Paint panel to make frame-by-frame animations

To animate frame by frame in After Effects from scratch, you must work with the Brush tool. Remember that to enable it correctly, you first need to create a Solid background (Ctrl + Y/Cmd + Y), go to the Timeline, and double-click on its Layer.

When the Brush tool is enabled, activate the Paint panel by hitting Ctrl + 8 or Cmd + 8 if you work on macOS. You must recognize the options in this box when you want to illustrate and animate simultaneously, especially the three tabs you'll find under the Opacity and Flow options. Focus on the Duration tab.

Changing the brush duration to animate frame by frame

Below the Mode and Channels tabs, you will find the Duration tab. This property determines how long a stroke will last in your project, meaning that if you leave this option set to Constant, whatever you draw on your layer will be maintained for the duration of your video. 

With that in mind, the next step is to change the duration of your brush. To do so, choose Single Frame so that whatever you start drawing in a single pass will only be part of a single frame of your project. Try it this way:

1. Now that you have chosen Single Frame in the Duration option, double-click on the Solid background layer and activate the Brush tool by clicking Ctrl + B or Cmd + B.

2. Draw whatever comes to your mind on your canvas.

3. When you have your first illustration, switch frames by clicking Ctrl or Cmd and the Right arrow key.

4. See how there is a blank canvas again? Draw your second illustration.

5. Repeat steps 3 and 4 as many times as you want.

6. When your drawing sequence is ready, return the Time Indicator to the beginning of the Timeline and hit the space bar to play the frame-by-frame animation.
   

To set a custom duration for your drawings to save time, go to the Paint panel, hit the Duration tab, and then change the Single Frame option to Custom. Do you see a box with a blue highlighted value next to it? Type in the number of frames (not seconds) you want your illustration to last.

Remember to take into account the frames per second (fps) of your video, so you know how many illustrations you need to do to complete a single second. Generally, After Effects defaults projects to 30 fps, meaning that you would need 30 drawings to cover one second of your footage.