https://www.conservationresources.com/shop/012-microchamber-folder-paper-155-lb-250g-m2-48-x-72/
.012 MicroChamber Folder Paper (155-lb., 250g/m2), 48 x 72 - #MC012-4872 | Conservation Resources
This paper was developed so the advantages of MicroChamber technology could be made available in standard archival folders. It has all the archival properti ...