In the strips, they had no need to think of their work in three dimensions or how they moved, but at the same time this extra aspect gave them the opportunity to introduce gags and elements not possible in comic stills. Moreover, because the drawings had to be mass-produced to create the illusion of movement, they had to come up with a compromise where characters were less detailed and time consuming, but at the same time alive and complex enough. As animators gained experience through trial, error and collaborations, cartoons became more professional and dominated by specific rules of how to make them.