HP has increased the thickness to 10 mil. They've textured the back of the paper so that the photos won't stick to each other when stacked (which one invariably does with snapshots). But, most importantly, using this paper will extend the archival life of my photos out to 75 years when using HP's new six-color printing system (available on the Photosmart 7550, and other current generation HP ink jet printers), which was verified in independent testing by PC World magazine in their November, 2002 issue.