I have a Grex airbrush. It's a gravity feed model. You can read my review of it. Previously I used a Paasche siphon feed airbrush. I hold a mold a foot or more away from me when I spray. As I said, there is some overspray but not a lot, and the box catches most of it. My impression from comments on eGullet from people who do not work in professional settings (that is, they mostly make chocolates in their homes) is that they do not have ventilation systems. I am not saying this is an ideal situat