A very thick, binder-free microfiber glass filter paper used in laboratories for fine particle retention.
(e.g., tax, engineering, or a school subject), I can give you more specific instructions on how to find or create it. Glass Microfiber Filter Paper, Grade 121, Ahlstrom - VWR
A heavy-duty, greaseproof, and waterproof creped kraft paper used for wrapping metal parts and precision equipment for long-term storage.