Exposure is really more an art than a science. Often times my main light is a full stop or more "underexposed" relative to the meter reading, but that gives me the desired effect for a portrait. The meter gives me a ballpark reading, and then the lights are tweaked for effect using digital or Polaroids.
I've also shot a lot of paintings over the years, and I can't see why anyone would do this kind of work on film. Digital is just way too good with white balancing and the ability to manipulate specific colors for matching the artist's vision. For this, the meter just confirms that the exposure is totally consistent from corner to corner, and for that the dome is always up.