2. Then, in the open software tool panel, find and select "Select Tool", as shown in the figure.
3. Then create a rectangular selection, and a rectangular ant line selection box will appear on the canvas, as shown in the figure below.
4. Select a watercolor pen on the tool panel, then set the size of the pen to be larger, and select a sharp nib, as shown in the figure below.
5. Finally, draw a picture on the canvas, as shown below.