hardshell

Hardshell refers to a rigid, protective outer covering used to protect the interior from damage and moisture. The term is applied to both biological structures and manufactured products.

In biology, hardshells are external skeletons or shells that provide protection and support. Many arthropods have hard exoskeletons made of chitin, reinforced with minerals. Mollusks such as clams and snails have calcareous shells. Some hardshells grow as the organism ages and are moulted or expanded to accommodate growth. Hardshells can also assist in camouflage, thermoregulation, and buoyancy.

In consumer goods, hardshell describes rigid protective enclosures. Hardshell outerwear uses a waterproof, breathable membrane beneath a stiff outer layer to keep rain out while allowing moisture to escape. Hardshell cases and luggage use rigid plastics or composites to protect contents, often with foam padding and secure closures. Hardshell gear is valued for durability and impact resistance but can be heavier or less flexible than softer alternatives.

The term is sometimes used broadly to describe any durable, nonflexible shell, including protective armor or sports equipment. It is distinct from softshell varieties, which emphasize flexibility and stretch over rigid protection.