Custom Concepts designed a product known as the Magic Crystal Ball as a premium for use by McDonald’s restaurants in some of its children’s selections on its menu. As designed, the Magic Crystal Ball was to be a hollow plastic ball enclosing a paper cube. The child-player was to “ask a question” of the ball, shake it, and turn it upside down to read an answer printed on one of the faces of the paper cube. Plastic Products agreed to manufacture the Magic Crystal Balls for Custom. Working from drawings supplied by Custom, Plastic produced a prototype that was approved by Custom and McDonald’s and passed a safety test by U.S. Testing, a laboratory that evaluates consumer products for quality and safety. 

Plastic then accepted a purchase order to make 1,785,500 of the crystal balls and began production. However, the production-run crystal balls failed the safety test because Plastic had thinned the edges of the walls so that its injection molds would fill uniformly. Custom had Plastic hold production, and then McDonald’s canceled its order because of time constraints in the promotional campaign of which the Magic Crystal Ball was to be a part. Custom notified Plastic that the project was off and brought suit against Plastic alleging breach of warranty. Did Plastic breach an express warranty when the production crystal balls did not conform to the prototype?