Smear frame

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Smear frame

A smear frame is a drawing used in animation to show motion blur between key poses. It stretches or duplicates parts of the subject to convey fast movement, making action look smoother. Smear frames have been used since the 1940s and helped reduce costs compared to other blur techniques.

History
- The most famous early use is in the 1942 cartoon The Dover Boys.
- Smear frames were developed for 2D animation and didn’t change much with the advent of CGI in the 1990s.
- The first notable CGI smear usage appeared in Hotel Transylvania (2012).
- A documentary textbook researching smear frames appeared in 2024.

Types of smear frames
- Elongated inbetween: stretch and distort the subject for 1–2 frames between key poses. The term comes from The Animator’s Survival Kit.
- Multiples: duplicate parts of the subject along the motion path, used for repeated actions like walking.

Smear frames in different media

In 2D animation
- Road Runner cartoons by Chuck Jones used smear frames.
- The Animator’s Survival Kit is a key reference on technique.
- The Legend of Korra mixed slight smears with motion blur.
- Super Science Friends used multiple copies of models to avoid distortion in 2D puppetry.

In 3D animation
- Hotel Transylvania (2012) used elongated inbetweens and multiple smears.
- The Lego Movie (2014) used Lego shapes in the same color to simulate smear.
- Into the Spider-Verse (2018) combined squash-and-stretch with overlayed 2D effects for smears.

In Stop-motion
- ParaNorman used 3D-printed head replacements in various smear shapes.
- Wallace and Gromit used multiples to depict quick actions.

In Video games
- Early games had limited power, so smears were rare; visually striking games with fixed cameras used them more.
- Sonic the Hedgehog (1991) smeared Sonic’s feet during runs.
- Crash Bandicoot used multiples and blur for spinning moves.
- Jak and Daxter (2001) used elongated inbetweens within limits.

See also
- Inbetweening
- Morphing
- Motion blur
- Onion skinning