When most people think about gas masks or respirators, what they usually envision is a tight-fitting plastic or rubber face mask with some sort of filter cartridge.

For example, you could program a filter that warps the surface of the image, creating an effect like that used on the cover of the Beatles' Rubber Soul album.

Screw the two sections together making sure the filter and rubber gasket are in place. This is important to ensure a perfect seal.