This document discusses common materials used in orthotics, including aluminum, rubber, plastics, adhesives, plaster of paris, leather, and fabrics. It provides details on the properties and uses of metals, specifically noting that metals like aluminum, iron, and alloys like steel are widely used due to their strength, conductivity, and other material properties. The document also summarizes properties of other materials commonly used in orthotics, such as rubber, plastics, adhesives, plaster of paris, and leather.