These are two books I have treated recently in the lab. Unfortunately, I got ahead of myself with these books and did not take before images.
This book was a half leather reback. The text block was a group of pamphlets sewn together and one section was exceptionally brittle. Initially, I tried to tip in the loose pages of this section with paste, but it was unsuccessful. It had to be removed from the group, washed and deacidified, then guarded and resewn into the text block.