The hide material used in the making of bicast is usually a portion of the fibrous, lower grade of leather that remains when the higher-grade grain layer is split off. Bicast leather is produced by building up a layer of plastic (typically
polyurethane) on top of an embossed
release paper known as
casting paper. Split leather is then pressed into the plastic. After the resultant bicast leather has cured, the casting paper is removed, and optionally re-used. The embossing usually gives the appearance of top grain leather, although it may be smooth depending on the desired finish. New bicast leather can have a chemical odor, but this typically dissipates about a week after the piece is exposed to air. Furniture manufacturers say that the main benefit of bicast leather is its surface appearance at a low price. With constant use, however, the polyurethane layer may crack and split free of its backing, and abrasion may cause large unsightly marks. ==See also==