The trick with RabbeSpace is to use either black foam board, black mat board, or black kraft paper as the last layer in the frame.
Tape seal the glass, art and backing package before putting it in the frame. Use the nice black RabbetSpace and the nice teeeeeny black plated screws that come with it and DON"T put a dust cover over it all. It will look very nice thank you.
The special drill bit availabe from FrameTek drills the right diameter and depth pilot hole in the frame and also drills a clearance hole through just the RabbetSpace to allow for a little expansion between screws. (Leave the screws slightly loose) The drill has a stop so you can't drill too deep.
There is a small groove in the RabbetSpace that you put the drill point into so that all the screw holes line up nicely.
The magnetic bit holder magnetizes the phillips bit to hold the teeeeeny black screws.
Watch the short video on the FrameTek web pages to see how to do it easily and quickly.