You have a couple of choices. Most paint booths use supplied air. It's just that, a full face respirator and compressed air with a regulator being pumped into your face mask. Lot of painters like it because it's like have a cool breeze flowing over your face and keeps you cool. The positive pressure created in the face mask helps keep all the particulates and organics out. If you don't have that, then you'd go to a half face respirator or still, a full face respirator. Here is where most people get confused, the cartriges. With painting, you going to have particulates, dust, mist and vapors. Those simply mean particle size in microns. You will need at least a particulate filter on your face mask to protect you from the dust and mist. You will also need an organic cartridge. These are simply activated carbon cartridges. Activated carbon is the cheapest and most efficient way of getting rid of volatile organic carbons, that's the smell the comes off the paint, if it is non-latex based. Most people don't know this, but there is some enamel paint mixed in with latex paints, just very small percentages. Those cloth looking, rubber band behind the head type of mask are only for particulates and will do nothing for VOC's. If you paint booth has great ventilation, I'm talking over 100cfm blowing past you and you can stay "upwind" while your painting, then you may be able to get away with a particulate type of filter, but it's up to you. As some the other posters said, paints are really nasty and you need to avoid any possible contact with them as best you can and a particulate filter only is not best achievable control technology in my book. The filters also need to be approved by OSHA and/or NIOSH, I forget the order of things.