If you've ever applied liquid eyeliner, you'll probably have a good handle on how an eyebrow marker works. This product is the same consistency as liquid eyeliner, but is designed to fill in eyebrows rather than line the lids. Eyebrow markers, sometimes known as eyebrow pens, feature self-inking, fine-point tips that can be used for everything from drawing individual hairs to creating thick, bold lines. To create natural-looking brows, use short, light strokes to fill in sparse areas in the eyebrows, and then feather the strokes slightly outside your existing brow line to add width where you need it.
Keep in mind that an eyebrow marker requires practice -- don't expect to spend 30 seconds slathering on a few generous strokes and end up with the look you want. Plus, liquid eyebrow fillers tend to dry quickly, which can make it difficult to correct mistakes. That said, many users like eyebrow markers for their staying power. Once applied, they'll last all day. [source: Robertson].