SKI*

Skis were originally wooden planks made from a single piece of wood. They are now usually made from a complex assembly of components including glass fibre, Kevlar, aluminum, other polymers, and composite materials such as carbon fiber, though many contain wood cores. Nearly all modern skis use a running base of high-molecular-weight polyethylene, and alpine skis use carbon-steel edges. These components are put together through a variety of ski manufacturing techniques.Most skis are long and thin and curve upwards at the front to prevent digging into the snow. The skier is attached by bindings which latch ski boots to the skis. Beginning in the early 2000s, many ski manufacturers began designing skis and bindings together, creating an integrated binding system. These systems serve three purposes. Firstly, they often use a railroad track design, to allow the toe and heel pieces to slide, which in turn allows the ski to flex deeply, without a non-flexing spot underfoot due to the binding .Secondly, it gives the skier a better control on his skis, since the binding is not only screwed on the ski, but integrated in the ski core via inserts. Thirdly, it requires the consumer to purchase both skis and bindings from the same manufacturer due to the proprietary nature of the system, thus increasing sales.