Lip Semi-Sync: The Incomplete Guide to Mouth Flapping

In the Aurora Picture Show workshops where I teach stop-motion animation to elementary-age animators, we work exclusively on paper, without the luxury of individual student workstations, and there isn’t enough time to produce projects with traditional, 9-mouth-shape lip sync of the classical Disney variety. Instead, we use a haphazard, 2-shape method I like to call “mouth flapping”. Is it perfect lip sync? Far from it. But it’s a gentle introduction if you’ve never tried lip sync animation before, and even in the context of an actual project (especially one with a lo-fi, handmade aesthetic, where the focus is on storytelling rather than technical perfection), I think you’ll find it’s a good thing to have in your toolbox.


The closed-mouth/resting position [L] is drawn onto the character itself. The open-mouth position [R] is achieved by cutting an oval out of a separate piece of paper that is the same color as the closed mouth, and at least as wide (if not slightly wider), then placing the replacement mouth on top of the drawing of the closed mouth temporarily.

As a first test, working at a rate of 12fps, try shooting five  frames with the closed mouth, then three to five with the open mouth, then two with the closed mouth, then four with the open mouth, making a variety of closed-open time combinations. You can edit these bits later to match your footage a bit more closely.

For emphasis, and to add a bit of visual interest to the shot in the example, I decided to shake this character back and forth while he was talking. This added motion made it harder to edit afterward, but the overall effect is just much more dramatic than a static body with a flapping mouth. The final shot was about 5 seconds long. Here are the first 24 frames as a GIF, followed by the whole shot as a video, which comes from “The Spies”, a film made over the Summer of 2016 at Wesley Community Center, during an Aurora Picture Show residency. The sync isn’t exact; there are places where the open mouth and the words you hear aren’t lining up at all. The mouth even opens once after the line has ended. But we’re not going for perfection here, we’re embracing accidents and mistakes in the interest of taking a small step forward.


Dave Merson Hess

Dave Merson Hess

Dave has worked in independent animation as a director and composer. He's taught workshops and/or developed curriculum for film-arts non-profit Aurora Picture Show, Rush Process Fest, DIY Animation Club, Zine Fest Houston, comedy incubator BETA Theater, Houston Independent School District, and the arts-in-medicine programs at Texas Children’s Hospital and MD Anderson Cancer Center.
Dave Merson Hess

Leave a Reply

Your email address will not be published. Required fields are marked *