This picture can be made with PS or AI. It is a vector picture. The black edges with different thicknesses are recommended to be drawn in PS. It will be very convenient if you have a hand-painted tablet. If you use it directly in PS Just draw one with a brush. Put this picture on the first layer. Open another layer and lower the transparency. Then you can see the pattern below. It’s the same as drawing red when you were a child. In this way, you can draw exactly the same as this one. . If you don't have a hand-drawn tablet to do the appropriate amount in AI, first use a pen to outline the edges and then fill in the colors.