Savarnas Mantras one brow primer can work in several ways. This pencil can provide a base for the brow powder and help the brow powder stick to it. It can also be used for superior adhesion and waterproofing. It can be used to draw on a brow first, with or without an eyebrow stencil. It can also be used to simply mark from where you want the brow to begin and end before applying the brow powder. The brow primer can also be applied to coverage your grey or white hairs.