Sure Cavity forms a rain screen drainage plane. The adhered fabric blocks mortar or stucco from filling the drainage channels and acts as a bug screen at terminations. It has superior appearance on thin veneers vs. furring strips due to less ridging, cracking, and waviness. High impact polystyrene ensures durability, rigidity, and longevity. Vertical channels promote rapid drainage and perforations allow cross-ventilation for better drying. Compartmentalized channels promote pressure equalization.