May I separate on Shabbos two pages of a book that are stuck together?

May I separate on Shabbos two pages of a book that are stuck together?

It‘s forbidden to separate on Shabbos two pages of a sefer (book) that have been attached to each other since production, because doing so would be transgressing the melachah of makeh b’patish (putting a finishing touch to something), in this case to the sefer. However, this prohibition does not apply to pages that got stuck together at a later time, and certainly not to pages merely clinging to each other as result of pressure (unless we will be erasing letters as a result of separating the pages). This is because they were never meant to be connected, and they adhered to each other only by chance.

A related action that falls under makeh b’patish is folding a magazine or a wedding invitation that came from the printer and still has to be folded on the scored line. It’s questionable whether one may bend the stiff binding of a new sefer in order to loosen it. #496

https://halacha2go.com?number=496

Practical Halacha: One minute a day. By Horav Yosef Yeshaya Braun, shlita, Mara D'asra and member of the Badatz of Crown Heights.