US Library of Congress about
"Preservation of Discs"
Most record sleeves should be replaced with a high density polyethylene such as DiscWasher V.R.P., Mobile Fidelity Original Master Sleeve, or Nagaoka No. 102 Anti-Static Record Sleeve. If an original paper sleeve contains text or graphics, the Nagaoka sleeves are thin enough to fit inside the paper sleeve.
Some plastic or plastic-lined sleeves should not be used. As a rule of thumb, "bad" sleeves are clear and have a sticky or tacky feel whereas "good" sleeves are frosted in appearance and have a slippery feel.