I've seen this done to badly deteriorated paper with japanese tissue tape, eg https://www.preservationequipment.com/Catalogue/Conservation-Materials/Labels-Tape

I've seen this done to badly deteriorated paper with japanese tissue tape, eg https://www.preservationequipment.com/Catalogue/Conservation-Materials/Labels-Tapes/Invisible-Paper-Repair-Tape https://www.preservationequipment.com/Catalogue/Conservation... and it did a pretty incredible job. There's a video on the left of that page that shows the process, worth a look.