These archival quality, static-free rice paper sleeves are a great choice for protecting your precious record collection. The rice paper adds a nice rigidity to the inner sleeves, and is sandwiched between two layers of 30 micron (appx 1.2mil) High Density Polyethylene (HDPE), with another layer of 30 micron protecting the other side of your 7" record. This is a total of over 3mil plastic protection! These sleeves provide the best qualities of inner sleeves made out of paper or plastic.