Smart tile comes in sheets 10x10, I believe. All I did was scrub the wall to remove any dirt and grease, I left the border on the wall. It seemed pretty solid when I attempted to remove it. It was a little difficult to maneuver to stick the tiles around the range hood but the end result is worth it. There is room for error as the busy nature of the pattern allows for adjustment without any notice. Had my critical son try to find a mistake I had made, he couldn't find it. Although it was a grout line I had to eliminate to get the tile back to plumb. If I didn't know where to look, I would have a hard time finding it.