I love these little books, they are the perfect size to bury in your back pocket and seem to be holding up to quite a bit of abuse being sat on and dropped and tossed every day.  The paper is a heavier gauge than most little notebooks so my fountain pen ink doesn't soak through.  The pages are perforated which helps to remove them without compromising the spine.  They are pretty small which i think is perfect at only 4"x2.5".