<Li> Racing / Alpine: Long, narrow, rigid, and directional shape . Used for slalom and giant slalom races, these boards are designed to excel on groomed slopes . Most often ridden with a "hard" plastic snowboard boot (similar to a ski boot), but also ridden recreationally with soft boots, particularly by riders in Europe . </Li> <Li> Splitboard: A snowboard which splits in half lengthwise, and allows the bindings to be quickly connected to hinges aligning them longitudinally on the board, allowing the halves of the boards to function as cross country skis . Used with removable skins on the base of the board, which easily slide forward on snow but not backwards, they allow a snowboard to easily travel into the backcountry . Once the rider is ready to descend, the board halves can simply be joined back together . </Li> <P> Snowboards are generally constructed of a hardwood core which is sandwiched between multiple layers of fibreglass . Some snowboards incorporate the use of more exotic materials such as carbon fiber, Kevlar, aluminium (as a honeycomb core structure), and have incorporated piezo dampers . The front (or "nose") of the board is upturned to help the board glide over uneven snow . The back (or "tail") of the board is also upturned to enable backwards (or "switch") riding . The base (the side of the board which contacts the ground) is made of Polyethylene plastic . The two major types of base construction are extruded and sintered . An extruded base is a basic, low - maintenance design which basically consists of the plastic base material melted into its form . A sintered base uses the same material as an extruded base, but first grinds the material into a powder, then, using heat and pressure, molds the material into its desired form . A sintered base is generally softer than its extruded counterpart, but has a porous structure which enables it to absorb wax . This wax absorption (along with a properly done' hot wax'), greatly reduces surface friction between the base and the snow, allowing the snowboard to travel on a thin layer of water . Snowboards with sintered bases are much faster, but require semi-regular maintenance and are easier to damage . The bottom edges of the snowboard are fitted with a thin strip of steel, just a couple of millimeters wide . This steel edge allows the board to grab or' dig into' hard snow and ice (like the blade of an ice skate), and also protects the boards internal structure . The top of the board is typically a layer of acrylic with some form of graphic designed to attract attention, showcase artwork, or serve the purpose similar to that of any other form of printed media . Flite Snowboards, an early designer, pressed the first closed - molded boards from a garage in Newport, Rhode Island, in the mid-1980s . Snowboard topsheet graphics can be a highly personal statement and many riders spend many hours customizing the look of their boards . The top of some boards may even include thin inlays with other materials, and some are made entirely of epoxy - impregnated wood . The base of the board may also feature graphics, often designed in a manner to make the board's manufacturer recognizable in photos . </P> <Dl> <Dd> See also: Board Construction </Dd> </Dl>

What is the base of a snowboard made of