Lasseter also explained that the film started with pencil and paper designs, saying: "Truth to materials. Starting with pencil-and-paper designs from production designer Bob Pauley, and continuing through the modeling, articulation, and shading of the characters, and finally into animation, the production team worked hard to have the car characters remain true to their origins." Character department manager Jay Ward also explained how they wanted the cars to look as realistic as possible, saying: "John didn't want the cars to seem clay-like or mushy. He insisted on truth to materials. This was a huge thing for him. He told us that steel needs to feel like steel. Glass should feel like glass. These cars need to feel heavy. They weigh three or four thousand pounds. When they move around, they need to have that feel. They shouldn't appear light or overly bouncy to the point where the audience might see them as rubber toys." According to directing animator James Ford Murphy, "Originally, the car models were built so they could basically do anything. John kept reminding us that these characters are made of metal and they weigh several thousand pounds. They can't stretch. He showed us examples of very loose animation to illustrate what not to do."