Koh-i-Noor Ruling Pen for Drawing is used for drawing precise line and borders with ink, watercolour and gouache and can also be used for applying masking fluid.

The variable line widths are set by a screw adjustment.

The penholder is made from black plastic, pen and bolt & nut are metal nickel coated.

Line thickness varies from 0.2 to 0.8 mm.