Painting protection is an important part of the painting process. Avoid straight taping borders near the paint lines and use a sanding primer if you need straight borders. For the paint border, leave the protective paper so that you can only tape it to the edges, creating a pocket in the middle, allowing the paint mist to penetrate and prevent the formation of a high border.
If you are fading the area, lightly tape the bag to the outer protective papers, making it easy to remove it from the road when fading. The protection can be thought of in layers: first, large areas are protected with protective plastic, then the area where the paint is bordered is protected with paper, and lastly, a bag detached from the surface is placed to soften the borders at the border of the paint area.