Danessa Myricks Linework Pen in Onyx shade is a highly regarded product amongst discerning make up artists!!  It has a  paintbrush tip, is  waterproof and smudge proof so can create flawless precision eyeliner looks. It has a gorgeous dark black semi matt pigment and the paintbrush tip allows smooth and easy application for the make up artist. 

The unique paintbrush tip is designed with 560 tapered bristles and 'ever flow' technology allows smooth  continuous application with one easy flowing movement of the pen.  This is a long lasting product which contains a flexible film seal to ensure long lasting wear. 

To use it, simply give the pen a shake first before application and if you want to create a thicker line just apply a bit more pressure and use full length of brush head. For thinner lines, just use the tip of the brush.