Painting fine lines

I need to know the best method for painting fine stripes around ordinance (bombs, drop tanks ,etc.) Masking them is difficult since they are funnel shaped and hard to get at. And buying tape in all the colors necessary isn’t really a good option. Anysuggestions? Thanks.

There was an article in the Dec 2002 FSM page 39 about making a small motorised lathe type devise for this very purpose!