Do you need to outline shapes? If so you need a liner brush. This kind of brush is short and narrow, has short handles and round ferrules. It is useful for delicate lettering, highlighting, outlining, and long continuous strokes. You can use it with watercolor, decorative ink or sign paint. I hope you like it!
Things You’ll Need:
- liner brush
- paint
- With a liner brush you can create several different line widths. Just vary the pressure on the brush. Try it out and you will be surprised.
One of the best ones is the Da Vinci Maestro Kolinsky Special Inlaid Liner Brush. You can get them at an art store, like Dickblick. 
Creating a line
Using a light pressure with just the tip of the brush on a surface creates a thin line.-
Creating a wide lineIncreasing the pressure, the line gets thicker and you can create the widest line on the surface.
different pressuresNow if you vary the pressure throughout one stroke, you can create a line that will be different in its form. You just change the pressure change from thin to medium to heavy and then back to thin. This is very good if you need to out-line shapes or when painting vines.
