While watching the Nascar race I was surfing the web and came across this post from a home theater forum. They were discussing painting a projector screen with pearl paint and this statement caught my eye:

"..One trick to rolling any Pearl/Metallic paint is to BEVEL THE NAP at both ends of your roller..... the final 1 inch is enough to bevel.... so as to reduce/eliminate...... the edge/line .....the bevel will help feather out the edge that normal rollers leave with this kind of paint.
[PS I undestand beveled roller tubes are available commercially but may be hard to find.]

Now to search for a double beveled foam roller.

Painting with Pearl