Entirely too many! I had to take a break before my putty knife hand was permanently in the shape of a claw. Good grief! Tack holes, small nails, big nails, tiny gouges, Grand Canyon gouges...and I'm only PARTIALLY done with 4 feet out each way from one stinking corner. I did have to thank him for one thing though. I don't even remember how many years ago, he peeled every inch of the boarder off the wall. I found some spray on stuff today that has no problems removing the little bit of paper/glue that is left. Oy. It's going to be a long weekend.