Whether you spray or brush, one of the biggest problems faced is that of the darker color leaking under the tape creating a small but ugly mess.

One of the biggest tricks to the above problem is to lay down a coat of clear after you have masked the area(s) desired and let that dry thoroughly. This will do a great deal against the leaching under the masking. Usually eliminates it entirely.

David, I don't know about the plastic with dope either... I would go with traditional cellelose based masking tape.

Robert