What is the purpose of the onion skin?

The purpose of onion skin in animation and storyboarding is to display previous or next drawings as overlays, allowing artists to see multiple frames at once. This technique is essential for achieving fluid motion and maintaining continuity between frames. By using onion skinning, an animator can easily compare the current drawing with those that precede or follow it, making it easier to ensure consistent character movement and positioning throughout the sequence. This visual reference enhances the overall quality of the animation, as artists can make more informed adjustments to their work based on the context of the surrounding frames. This approach is especially useful during the planning phase of animation, where timing and movement arcs are crucial for effective storytelling.