Hashish is sometimes smoked by taking a bit, holding it up with a paperclip or a push-pin on a table, and trapping the smoke with a cup. Later the cup can be lifted and the smoke cleared with a straw. This is called a Glass Lung. A variation involve the same cup or glass and placing the hash within it, open side up. The open mouth is covered with something flat and relatively thing like a thin piece of cardboard/posterboard. When the glass fills with smoke, slightly pull back the cover and 'sip' the smoke out.