The popularity of soft drinks, juices, sports beverages, and bottled water is responsible for the use of millions of PET bottles daily in the U.S. For manufacturers of these containers, this has been good for business. Brand managers wanting to distinguish their product have turned to color as a means of gaining brand differentiation. PET bottles are seen in more and more colors. Naturally, this has resulted in a need to specify and communicate color while also setting limits on acceptable color variation in production. Maintaining the exact color of the final blown bottle starts with getting the color right in the preform stage. The preform is the test tube-like piece of molded plastic that is blow-molded to form the final bottle. If the color is not correct in the preform stage, it cannot be "fixed" in the final blown bottle phase before shipment to the bottler. Catching a color problem and resolving it before the shipment is made, saves time, money, and leads to a better vendor/supplier relations.