In pursuit of Preservation information, a recent patron applied tape to the pages in order to then underline what they deemed significant passages.
Was this to protect the paper? We don't know. We do appreciate they did not want to actually write on the page itself, it not being their personal book, but tape is just as harmful to the printed page, if not more damaging.
Pressure sensitive adhesive materials leave a residue and cause the deterioration of the fibers in paper. These include all variety of sticky notes and every kind of tape, even if the manufacturer has marketed it as a repair material.
Tape is tape is tape...
and will ultimately cause harm to those special materials you are trying to preserve.
(We recommend using thin Japanese paper and rice starch or wheat starch paste to repair torn pages.)
Luckily, after some careful use of tools, we were able to remove this harmful material from the book's pages. This time...