kayak is a small, relatively narrow, human-powered boat primarily designed to be manually propelled by means of a double bladed paddle. The traditional kayak has a covered deck and one or more cockpits, each seating one paddler. Their cockpit is sometimes covered by a spraydeck (or "skirt") that prevents the entry of water from waves or spray and makes it possible for suitably skilled kayakers, to roll the kayak: that is, to capsize and right it without it filling with water or ejecting the paddler.

  Some modern boats vary considerably from a traditional design but still claim the title 'kayak', for instance in eliminating the cockpit by seating the paddler on top of the boat ("sit-on-top" kayaks); having inflated air chambers surrounding the boat; replacing the single hull by twin hulls ("W" kayak), and replacing paddles with other human powered propulsion methods, such as foot-powered rotational propellers and 'flippers'. Kayaks are also being sailed, as well as propelled by means of small electric motors, and even by outboard gas engines, when possible.

　Kayak brand labels are pvc labels to suit the material.PVC labels, which is the world's largest production of plastic products, the price is cheap, widely used. The material is PVC resin, a white or pale yellow powders, this material can be added different physical and mechanical properties. Adding an appropriate amount of plasticizer in the polyvinyl chloride resin, can be made into a variety of hard, soft and transparent products. 

  kayak design is largely a matter of trade-offs: directional stability ("tracking") vs maneuverability; stability vs speed; and primary vs secondary stability. This is true for single hull (a.k.a. mono-hull) kayaks, but does not necessarily encompass newer types of hulls, such as twin hulls.