A waterproof, non-breathable shell layer is also referred to as a?

A waterproof, non-breathable shell layer is appropriately referred to as a waterproof barrier. This type of layer is specifically designed to prevent water from penetrating while maintaining its overall waterproof characteristics. This material plays a critical role in protecting wearers from external moisture, such as rain or snow, while being used in various outdoor activities, including search and rescue operations.

In the context of fabric and clothing design, a waterproof barrier does not allow moisture in but doesn't allow moisture out, meaning it does not facilitate vapor exchange. This characteristic is essential in cases where exposure to wet conditions is expected, helping to keep the user dry.

The other terms listed do not accurately describe the waterproof, non-breathable nature of this layer. A vapor barrier typically refers to materials that prevent water vapor from escaping or entering, often used in specific construction or insulation applications rather than fitting into outdoor gear. A moisture trap generally indicates a layer that retains moisture, which contradicts the purpose of a waterproof shell. Lastly, an insulation layer is designed for thermal protection and may not necessarily be waterproof or non-breathable.