Engineered wood siding and flooring and composite lumber are generally the newest and least familiar forms of wood products, but are gaining in popularity because of environmental considerations. Most of these materials bond wood or other kind of cellulose fibre into a specified shape. The most common kind of siding is 100 percent wood, made from planer shavings, sawdust or other wood by-products from sawmills. In the case of Southern pine, it is cooked under heat and pressure, and turned into a fibrous pulp that is then formed into a mat, trimmed and placed in a press. Under heat and pressure, the presss engraving plates produce one of a variety of surface textures,