I bought a really beautiful painting for my new flat. I needed to put the painting up on the wall to display it. I  found the perfect spot on the wall that I wanted to put it on. I went to my tool bag and got a hammer, a nail, a piece of chalk, and a leveler. I marked the spot I wanted to put the nail in with the piece of chalk I had. I carefully put the nail on the spot, then took my hammer and hit it a few times. When I checked to make sure it was going in straight, I kept hammering it in. I hammered it in until it was half way in the wall and half way not. I put the hammer down. I picked up the painting and hung the frame on the wall. I then took the level and made sure it was even. When I was sure I had it hung even, I put my tools away.
Why did they hang the painting?