I have found that displaying my artifacts on plexigl**** gives the impression of the item floating in air and allows for back light.  The artifact is attached with sticky velcro.  This does not hurt the artifact.  
I have also found the main downside to curios is that the light only goes down a couple feet and the artifacts at the bottom do not get any light.  If you use frosted gl**** shelves spaced about 3" apart and place a florescent light between them you will up and down light each shelf. 
Thanks 
Greg