i've found a much better solution to screen, as the only ones you'd rather have to carry around and take chances losing are the metal ones, and that's just to take a corner of toilet paper, fold it up perfectly to just barely get through the hole in the mouth-peice... it kinda acts like a cigarette filter but not quite... i still get high as hell (if i use a cigarette filter in a joint i DO NOT get high, well i've never actually rolled a filter in ajoint, more refering to stuffing an empty cigarette 'shell' with bud....

anyways, i just stuff a bit of TP into the pipe... it blocks all the ash/particles..