Adobe Illustrator / Watercolor Art Brush
- Double-click on Pencil Tool - Fidelity: 0.5px, Fill new pencil strokes, Keep selected
- Draw a shape of a brush stroke and fill it with light gray
- Draw a shape of a larger brush stroke and fill it dark gray
- Draw a shape of the largest brush stroke and keep it transparent
- Align and select all the shapes
- Object > Blend > Blend Options - Smooth Color
- Object > Blend > Make
- Set the blended shape to Multiply in Transparency Window
- Drag the blended shape into Brushes Window - New Art Brush, Method: Tints
