Bobbi Brown Ultra Fine Eyeliner Brush A slim, finely tapered shape and firm bristles make this brush ideal for creating precise, crisp lines with gel and powder eyeliner formulas. Slender design offers ultra-fine precision when lining eyes. Firm, densely packed bristles enable wet-dry lining with gel and powder eyeliner. How to use Dip the tip of brush... Dip the tip of brush into gel or powder eyeliner and apply in short, even strokes close to the lash line, from outer to inner corner. Reapply for a thicker line, if desired. For wet lining, dampen brush slightly, then pick up powder formula.