The edges of the door are placed on the bent rods, these are bent the exact angle to result in minimum contact & therefore allows one to paint both sides at the same time. For cabinet doors we recommend to spray the backside first with a good-solid, but light coat then the front can be sprayed with a heavier coat. If there is a mark, it is so minute it can be touched up with a Q-tip or the tip of your finger, but after one coat of primer, and two coats of enamel, it usually doesn’t show any marks. With clear finish it leaves absolutely no marks. With big doors there is no issue. If you like you can ask any of the recommendations in our website! Explanation below