There are a dizzying number of brow products and services at our disposal aimed to get us lush and thick brows. But one treatment took Instagram by storm: microblading, the process of tattooing tiny brow hairs with a needle. We spoke with celebrity makeup artist and brow specialist (a.k.a The Eyebrow Doctor) Piret Aava to learn everything we need to know about the semi-permanent solution.

What is melasma and what does it look like?

Melasma is a common skin disorder. Loosely translated, the word means “black spot.” If you have melasma you’re probably experiencing light brown, dark brown and/or blue-gray patches on your skin. They can appear as flat patches or freckle-like spots. Commonly affected areas include your face, including the cheeks, upper lip and forehead, as well as the forearms. Melasma is sometimes called the “mask of pregnancy” because it frequently affects pregnant women. Melasma typically darkens and lightens over time, often getting worse in the summer and better in the winter.