There's a pair of suitcases available at Costco that are branded Samsonite. The small one is claimed to be 9" thick; however, when zipped (with the expansion zipper closed) it's over 10" thick (and the expansion zipper would add a couple more). Squeezing one corner together I get the hard sides to be 9" apart; however, I have found no method of compressing more than one side. Neither could a Costco employee I asked.

Am I missing something or did they just make a mis-sized suitcase?