Onion skin
What onion skin is in animation, how to use it to draw smooth frame-by-frame animation, and the settings that help. With a free animation app that has it built in.
Draw a frame, tap + for the next one, and change the drawing a little. The last frame shows faintly in red underneath (onion skin), so each drawing follows on from it.
Using onion skin to draw the next frame
- 01Draw your first frame and tap + for a new one.
- 02The last frame now shows faintly in red under the empty canvas: that's the onion skin.
- 03Draw the new pose moved or changed a little from the red one.
- 04Open the onion-skin settings to show 2 or 3 frames back, or the next frame in green when you draw in-betweens.
- 05Turn it off (or press O on a keyboard) to see the frame on its own.
What onion skin means
Onion skinning shows the frames before (and sometimes after) the one you're drawing, faintly, underneath it. It lets you see exactly how far something has moved, so each new drawing follows on from the last.
The name comes from hand-drawn animation, where animators drew on thin, see-through onionskin paper on a light table, so the drawings underneath showed through. Digital animation apps copied the idea, and the name stuck.
The settings, and when to use them
- One frame back (the default): enough for most drawing.
- Two or three frames back, fading: to keep the spacing even across a movement.
- The next frame, in green: when you draw an in-between, so you see the poses on both sides.
- Strength: lower it when the onion skin gets in the way of your lines.
- Colours: red is behind, green is ahead, so you never confuse the two.
Onion skin in stop motion
Stop motion uses the same idea with a camera: the last photo shows half see-through over the live picture, so you can move a figure a tiny bit each time. For that, our sister site Stop Motion Online has a free browser studio with onion skin over the camera.
Questions
What is onion skin in animation?
A view that shows the previous frame (or several) faintly under the one you're drawing, so you can see how far things have moved. It's named after the thin onionskin paper hand-drawn animators used on light tables.
Why is the onion skin red and green?
Red shows frames before the current one, green shows the frame after it. Different colours stop you from mistaking which drawing is which.
How many frames of onion skin should I show?
One frame back is enough most of the time. Show two or three, fading out, to judge spacing across a movement, and the next frame when you draw in-betweens.
Does onion skin show in the exported video?
No. It's only a drawing guide in the studio. Your video shows only the frames you drew.
Are my drawings uploaded anywhere?
No. Your drawings, frames and the videos you make all stay in your browser on this device. Nothing is sent to us or stored on a server.