Composite handles of rigid plastic and rubber are also common. Optical discs are made of polycarbonate plastic and aluminum. Drums are cylindrical shipping containers made of steel, plastic or fiber. Number plates are available in plastic or metal. The pattern is made of wax, wood, plastic, or metal. It can be made from many materials, including metal, plastic, and wood. The underwire is made of metal, plastic, or resin. This is usually made of plastic and or metal. Dimethylmercury is capable of permeating many materials, including plastic and rubber compounds. Child trikes have frames made of metal, plastic, or wood. These include items such as plastic grocery bags. Another was Plastico for plastic kitchen containers. They are typically made from rotomolded plastic, or fiberglass. Typical materials include glass, plastic, and fluorite. EVOH is used in multilayer films for packaging as a barrier layer (barrier plastic).