There are many variations to mouth movements. Of course, if you are working on a low-budget or experimental project using Claymation, you may simply want to roll out a pair of tubular lips and manipulate them with your fingers. If you prefer a more precise and detailed mouth, however, it all begins with the design of your puppet.
The best way to work with an animated mouth is to create the head of your figure without one. Construct several different mouths out of the same material as your character’s head. These mouths can be shaped according to the various looks your own mouth creates when you say certain sounds in front of a mirror. Do not be concerned about the prospect of having to make hundreds of different replacement mouths for each sound that humans create. If you make roughly ten to fifteen different shapes, you should be able to have enough movement to simulate the correct motion of a wide variety of dialogue.
Place a piece of plastic wrap, cut to the shape of the back of your mouths, on the front of the head where the attachments will rest. When you get ready to film each frame, place the corresponding mouth onto the plastic wrap. Use a knife to carefully pull the attachment off of the plastic wrap, and then use a replacement mouth for the next frame. The wrap should serve as a protective covering which is designed to keep the head and attachments from incurring damage throughout the switching process.
Another great tip is to create a single mouth, but insert teeth made of a harder, plastic material. If you need to move the shape of the mouth, you can carefully go in and press the teeth with a toothpick in order to manipulate the shape of the mouth without unwittingly smashing it with your fingers.
When your character does speak, remember that most people do not close their lips entirely between sentences. It is important to animate your character’s mouth in a semi-open state in order to avoid this problem.
To address the issue of lip-synching, you may find it helpful to utilize software such as Magpie or Crazytalk software. Both programs are designed to help you match your character’s movements to spoken dialogue.
If you do not wish to go into tedious detail with your animation, you can simply show a different camera angle when your character speaks. If you choose to focus on their profile, then you can easily animate a side view of the mouth without having to create as much movement as you would from a frontward-facing position.
Silence is golden, but it can result in a boring film with an unremarkable storyline. Creating a dialogue between your characters will give them a new life and personality with which to enrich your film.