Is there a thread that addresses long term X-Metal storage? Look at Hando's picture. See that left case there is a hard like seal-it foam. I would advise not using those for long term storage as the vapors react with foam vapors and can damage the frame. Using the velvet cases Hando's middle and right case, I would put them in a micro-fiber case just to be on the safe side. The following listing below (I'm not affiliated with the person), the last pictures illustrate the effect. Notice the lasts couple of pictures? The discoloration pitting of the frames in the last picture you can see the degradation of the foam. Current ebay listing as of 5/4/14 (somebody grab the photos for illustrative purposes)