Ah because I once had a stamp that someone went nuts with the ink on. It was a blue colored stamp and a tiny amount of the ink got mixed in a few of the bags producing a blue tainted mix. I didnt shoot mine but the guy i was with did, then spent hours freaking out. Nothing happened to him but I was thankful I was still in the "not quite addicted but still not above crying when I cant get it" stage and was able to spray it out rather then worry.