Heh. When I cleaned out my office, I made the mistake of getting boxes way too big for my books. I had eight boxes, some of which had to weigh at least 100 pounds -- I'm not exaggerating.
It was like a strongest man competition; by the time I carried the fourth box up the flight of stairs and into my apartment, my legs were wobbling like I was having muscle failure.
The next four stayed in the car until the next day.
Yeah, in a move, the boxes full of books are the heaviest.
In fact, my heaviest box full of books from the move is still sitting nicely in my closet. I'm scared to touch the thing.
The boxes I have are really bigger than I should be using for books! I've been sliding them around here...can't hardly lift 'em. I'm thinking maybe I should repack 'em before actually mailing. It's so easy to just toss books into a box without realizing how quickly the weight is adding up...
Considering how many books I have, even after paring down, the easier they are to move the better! Did discover today that the cardboard bin behind Barnes and Noble generally has a good supply of smallish book boxes, so I'll likely be raiding it again. I really should use those to replace the boxes the books are in now.