Swim trunks are the most common type of swim shorts. They are usually made of nylon or polyester and have an elastic waistband. Swim trunks usually have an inner mesh lining, open side pockets, and one or two back pockets. The fit is in the loose side and they end above the knees. The original trunks usually came in a single basic color. However, these days it's not uncommon for them to have abstract patterns, colorful prints, stripes, or full photos. The great variety in swim trunks makes them the standard choice for males of all ages.