A stuffed bear resembling Lotso can be seen in Toy Story (1995) during the staff meeting. Woody asks if the toys "up on the shelf can hear" him, and we see a shot of a big, pinkish bear. John Lasseter wanted to use Lotso in the original Toy Story, but Pixar had trouble getting the fur right.
Tom Hanks and Tim Allen insisted that they record their lines together, which they had previously done for one day during the making of the original Toy Story (1995), but which is rarely done with animated films. They loved the chemistry their characters shared on-screen.
By the time Toy Story 3 (2010) was made, Pixar animators had figured out how to animate things like water and fur. Although being able to realistically animate fur was originally a concern for Toy Story 3 (2010) animators, the real animation challenge was trying to animate the trash bags in the movie. Since trash bags have special properties, such as how it reflects light, animators spent weeks trying to get the trash bags correct.
Blake Clark became the new voice of Slinky Dog, replacing the late Jim Varney, who died of lung cancer in 2000. Clark and Varney had been good friends.
For inspiration for the Sunnyside escape, the Pixar staff watched numerous prison movies. Director Lee Unkrich said, "There are a lot of prison movies out there, and I think we watched every single one of them."