MoMA Learning

This pitcher and creamer are made out of injection-molded polyethylene, the simplest form of plastic. It is a thermoplastic, which means that, to form objects, the plastic is heated, melted, and then injected into a mold under high pressure. After the material has cooled, the mold is opened, and the object is removed. Although injection molding seems simple, the construction of the tools and molds, the consistency and flow of the molten plastic, and the objects’ cooling times must all be precisely handled to achieve the desired outcome.

Earl S. Tupper was the first to bring this process to the design and manufacture of household items such as food containers. Through his utilitarian designs for storage, Tupper hoped to make “woman’s lives” easier. Once he had designed their forms to his desired specifications, he developed a patented Tupper Seal, which enabled users to tightly close the containers to preserve the freshness of the food inside. Tupperware stackable food containers became popular in the United States in the 1950s because they were lightweight and affordable. Prior to Tupperware, all food storage containers were made out of glass and could not be firmly sealed shut.