Check with a good professional paint supply house. Quite a few years back, I had our house painted inside. We had some louvered doors between the family room and living room, and the painter had this neat little spray can the used aerosol cartridges and what ever paint he was using. It gave a spray pattern quite a bit bigger that an air brush, but still way smaller than he could get with his airless sprayers. That has been close to 15 years back, so the aerosol cartridges may be outlawed by now. It wouldn't hurt to look though.

Don