Floating effect framing:

Artwork mounts with acid-free glue or tape on a foam board and places on a back board. Due to the back board (underneath the foam board) is bigger than the artwork, there is a visible border surrounds the artwork. This visible border width is based on personal preferences. 

Acrylic glazing is raised up by strip at the rabbet in order to make some distance from the artwork. 

Artwork looks floating inside the frame.