Polycarbonate multiwall sheets are a type of plastic sheeting made up of multiple walls and connective ribbing that provide excellent thermal insulation. They are lightweight, durable, and shatter-resistant, making them an ideal glazing material for outdoor applications. They are often used in roofing, siding, and greenhouse panels due to their strength and ability to provide up to 60% more thermal insulation than glass. They also offer protection against UV rays.