Effortlessly brush on fuller-looking brows in seconds for a more youthful and lifted appearance using tarte Big Ego DIY Brow Detailing Pen. The easy-to-use liquid brow pen features a unique angled brush tip with ultra-fine, multi-length bristles designed to mimic the look of real hair, while also blending in with existing hairs. It instantly tints, fills in sparse areas, and creates definition to give the look of thicker, natural-looking and beautiful brows. How do I use it: The softer you press while applying, the lighter the shade. The harder you press, the darker the shade. First, brush up brow hairs using the included spoolie. Shake well, then hold pen at an angle drawing soft, hair-like strokes upwards to tint, fill, and define. From tarte.