I don't know about that. I have some really old filmholders with perfectly good felt light traps and things made of neoprene that have started to crumble in less than five years. I don't know if neoprene lasts longer in the dark, so that might be a consideration. I think felt might be a better choice in case of high humidity, when neoprene might cause the darkslide to get stuck on the way in or out.