and a high carbon XC90 steel (acier au carbone) blade. Opinel also offers most of its models with a Sandvik 12C27M stainless steel (acier inox) blade. Custom Opinel models are available using luxurious or exotic handle woods such as oak, walnut, olive wood, bubinga (African rosewood), ebony and stained hornbeam, as well as other materials such as cowhorn. The Opinel Slim Effilé series uses a tapered handle with a slender clip point blade made of Sandvik stainless steel, and the handle may be obtained in a variety of different materials, including bubinga, olive, ebony and cowhorn. Construction The current Opinel knife consists of a blade, wooden handle, stainless steel metal clamping band, stainless pivot pin (axle), and (except in the case of the smaller models) a stainless steel Virobloc locking collar, which locks the blade open or closed. Smaller Opinel models (Nos. 2 through 5) have no locking blade mechanism, and use only the friction of the clamping band against the compressed handle and knife tang to hold the blade open, much the same as all Opinel knives sold before 1955. This simple design was sometimes known as a "penny knife" or "peasant's knife". The locking collar (Virobloc) was patented in 1955 by Marcel Opinel, and is only found on the larger Opinel models (#6 and up). While simple, the locking mechanism is quite sturdy. Due to the way in which the locking collar tapers, the blade does not loosen over time and can be fixed firmly even once the mechanism is quite worn. In 2000 the locking collar was modified slightly to allow the blade to be locked in the closed as well as the open position. This feature prevents the blade from opening by accident when carried in a pocket. Eighty percent of all Opinel knives use traditional beechwood for the handle. The company's large demand for beechwood not infrequently results in a shortage of precut handle blanks, forcing the use of rectangular (bulk) sheets, which generate considerable wood waste. The excess wood waste and sawdust generated is subsequently recycled. Design and operation The curve of the original Opinel blade is a Yatagan (more commonly described as a drop point with a blade slightly angled downwards from the handle centerline), while the flared butt at the base of the wood handle is referred to as a fishtail. The modern No. 8 knife consists of 5 pieces (formerly 4);