I mentioned this in the Houston show thread a couple weeks ago, but I found a cool option for transporting or storing backglasses.
Anchorbox.com sells what they call Mirror boxes. This box has two pieces that slide together making it an adjustable size box. I bought what they list as a 30"x40"x3" box. The 40" dimension adjusts down to as low as 21". I was able to fit both bubble wrapped glasses for my Xenon in one box. Kept them safe during resto work.
Box sells for about $5 plus shipping. They have multiple sizes if you have other needs that they might fit. I'd expect most people can find something similar at a packaging vendor near them.