I paint my hives on the outside and edges with a good quality latex white
paint.  The bees will cover (and preserve in the process) the inside with
propolis.
 
Tom Fisher               | "The light that burns twice as bright
Purdue University        |  burns half as long....and you have
[log in to unmask] |  burned so very, very brightly, Roy."
                                                   - Eldon Tyrell