1. Masks and filters, neither one can be missing☆
2. The marquee does not have to be a rectangle. You can choose an oval shape or even draw a poop shape if you like☆
3. The values of each operation can be adjusted according to the situation, and there is no need to be too rigid☆
4. The effect is very different if the stroke is inside or outside☆ The shortcut key for quick masking is Q
