Shades: Espresso Martini and Jet Black
Steps: First, apply a base coat followed by two layers of the shade "Espresso Martini", then add a matte top coat to finish. Next comes the tricky bit, using a fine detail brush, create some freehand lines (or you can try striping tape if you aren't confident with freehand) in "Jet Black". To get the bold effect, apply a shiny top coat only over the black lines you created, this will give a contract between the neutral base and bold black graphics.
Image Source: Snail and Hare