[ Ref. Ralph Schultz in 250613 MMDigest ]

My understanding is that once paper is brittle it is irreversible.
The best practice is to reduce damage in advance using deacidification.

There is a product called Bookkeeper Deacidification Spray, available
from The Library Supply. I have no experience with this product, yet.

Their website says it "safely and effectively neutralizes acids in paper
to increase the lifespan of books and documents. The spray's magnesium
oxide neutralizes acid, leaving an alkaline reserve permanently fixed
in the cellulose fibers."

https://thelibrarysupply.com/products/bookkeeper-deacidification-spray-1 

Has anyone experience with this product? After I try it, I'll report
back.

Rev. Robert Linnstaedt
Ft. Worth, Texas