The sleeve is clear on both sides before and after the effect. The sleeve itself is pretty durable. It can definately be left in a pocket, and I can't imagine that water would damage it.
As for if the spectator questioning the sleeve, strangely enough, no, and I have no idea why!
Christian, if you want more details on the sleeve I can give you them in a PM, but I wouldn't want to post anything more here for fear of exposure
