A canteen is a drinking water bottle designed to be used by hikers, campers, soldiers and workers in the field. It is usually fitted with a shoulder strap or means for fastening it to a belt, and may be covered with a cloth bag and padding to protect the bottle and insulate the contents. If the padding is soaked with water, evaporative cooling can help keep the contents of the bottle cool. Many canteens also include a nested canteen cup.
Primitive canteens were sometimes made of hollowed-out gourds, such as a calabash, or were bags made of leather.
Later, canteens consisted of a glass bottle in a woven basket cover. The bottle was usually closed with a cork stopper.
Designs of the mid-1900s were made of metal â" tin-plated steel, stainless steel or aluminum â" with a screw cap, the cap frequently being secured to the bottle neck with a short chain or strap to prevent loss. These were an improvement over glass bottles, but were subject to developing pinhole leaks if dented, dropped or bumped against jagged rocks.
Contemporary designs are almost exclusively made of one of several types of plastics, especially polyethylene or polycarbonate. They are typically as light as, or lighter than, their metal equivalents and are quite resistant to developing leaks, even when dropped or severely bumped.
Hunter-gatherers in the Kalahari use ostrich eggshell as water containers in which they puncture a hole to enable them to be used as canteens. The presence of such eggshells dating from the Howiesons Poort period of the Middle Stone Age at Diepkloof Rock Shelter in South Africa suggests canteens were used by humans as early as 60,000 years ago.