Inbetweening, also known as tweening, is a process in animation that involves creating intermediate frames, called inbetweens, between two keyframes. The intended result is to create the illusion of movement by smoothly transitioning one image into another.
Traditional inbetweening involves the use of a light table to draw a set of pencil and paper drawings.
The process of inbetweening in traditional animation starts with a primary artist, who draws key frames to define movement. After the testing and approval of a rough animation, the scene is passed down to assistants, who perform clean-up and add necessary inbetweening. In large studios, assistants usually add breakdowns, which define the movement in more detail. The scene is then passed down to another assistant, the inbetweener, who completes the animation. In small animation teams, animators will often carry out the full inbetweening process themselves.
Dick Huemer developed this system in the 1