The entire Simpson family was designed so that they would be recognizable in silhouette. The family was crudely drawn, because Groening had submitted basic sketches to the animators, assuming they would clean them up; instead, they just traced over his drawings. Bart's original design, which appeared in the first shorts, had spikier hair, and the spikes were of different lengths. The number was later limited to nine spikes, all of the same size. At the time Groening was primarily drawing in black and "not thinking that would eventually be drawn in color" gave him spikes which appear to be an extension of his head. The features of Bart's character design are generally not used in other characters; for example, no other characters in current episodes have Bart's spiky hairline, although several background characters in the first few seasons shared the trait.