Hip flasks were traditionally made of pewter, silver, or even glass, though most modern flasks are made from stainless steel. Some come with small cups to make sharing easier, although generally liquid is drunk directly from the flask. They are usually contoured to match the curve of the wearer's hip or thigh, for comfort and discretion. Some modern flasks are made of plastic as to avoid detection by metal detectors.
A hip flask is most commonly purchased, and then filled by the owner. However, the term "flask" also applies to smallest bottle sizes of alcohol in commercial markets.
