12" White Polylined Antistatic Inner Sleeve
Paper Inner sleeves are generally designed to be softer and less prone to marking the record during insertion or extraction. These sleeves also have antistatic properties that are of considerable importance if you have static issues with your record player. A treated record, placed in an antistatic sleeve will stay treated.
Many modern releases come with a stiff cardboard inner sleeve that is well-suited for having artwork or lyrics printed on it, but less well-suited for the business of keeping the record stored in a way that keeps it free of scratches or other issues.