 In 2008 , the crew shifted to using Wacom Cintiqs for the drawings instead of pencils . The fifth season episode " Pest of the West " was the first episode in the series to which the crew applied this method . Series background designer Kenny Pittenger said , " The only real difference between the way we draw now and the way we drew then is that we abandoned pencil and paper during the fifth season " . The crew began the shift while they were working on the episode . Pittenger said , " It was while we were working on ' Pest of the West ' , one of the half @-@ hour specials , that we made the switch ... did you notice ? " The shift to Wacom Cintiqs let the designers and animators draw on computer screens and make immediate changes or undo mistakes . Pittenger said , " Many neo @-@ Luddites — er ... I mean , many of my cohorts — don 't like working on them , but I find them useful . There 's no substitute for the immediacy of drawing on a piece of paper , of course , but digital nautical nonsense is still pretty fun " . 
