Here's what I do with my pieces.   I do differentiate between high end art and standard art.   The high end pieces or ones that seem more condition sensitive, what I do is:   1) Use Acid Free Backing Boards = https://www.bagsunlimited.com/c-129-backings.aspx   2) Use Mylars = https://www.bagsunlimited.com/p-5164-11-x-17-original-comic-art-sleeve.aspx   Put the comic art with a board, then into a mylar.   3) Use Polybags = https://www.bagsunlimited.com/p-7353-13-x-19-original-ar