A brush for applying a substance to keratinous fibers may include a twisted core defining turns and bristles extending from the twisted core. The bristles may be clamped between the turns of the twisted core, and the bristles may include at least two deformed bristles clamped between two adjacent turns of the twisted core. Each of the at least two deformed bristles may have a length wherein at at least one point along the length each of the at least two deformed bristles includes either removal of material at the at least one point, stretching of material at the at least one point, or flattening at the at least one point. Each of the at least two deformed bristles may extend outward from the at least one point in a non-radial manner with respect to the twisted core.