Methyl cellulose is a powder that, when mixed with liquid, creates an adhesive.
It dries clear, is archival, neutral pH, nontoxic, vermin proof, does not decompose.
Mix with PVA glue to slow dry times and make it easier to work with. Also used for book repair, thickening water for paper marbling, bookbinding, and general archival adhesive applications. It’s easily reversed with cold water. Mixing instructions included.