They may be made of old plastic containers, wood, Styrofoam, or metal containers. The cheapest modern pillow is domed and made of polystyrene (styrofoam). The state of Maine ban Styrofoam (polystyrene) containers in May 2019. Mothra's silk was created from a form of liquid styrofoam called "expanded Polystyrene". Structurally, bread can be defined as an elastic-plastic foam (same as styrofoam). Styrofoam containers may release chemicals into the organic material. Some hobbyists build custom cases from raw materials like aluminum, steel, styrofoam, acrylic, or wood. Fisher built a prototype out of Styrofoam and epoxy. In colder climates, rammed-earth walls can be insulated with Styrofoam or a similar insert. In 2012, McDonald's announced they would trial replacing styrofoam coffee cups with an alternative material. Even a coated tile feels very light, lighter than a same-sized block of styrofoam. A debris field consisting of wood, cargo, styrofoam, and other objects was discovered that afternoon. In 1971, Nissan introduced instant ramen packaged in a styrofoam cup. The claimed R-value of Styrofoam insulation is five per inch. The wall around the Corleone compound was made from styrofoam.