The highlighter works similarly to a traditional highlighter. Use it to mark part of a picture with a colored line. A color and a color intensity can be set for every highlighter you use. To erase a part of the mask, click the Remove from Mask button that’s located among the Brush Settings. You can force the brush parameters to be the same in both modes, or let them be different – to toggle this setting, use Shared Brush Settings. To draw a horizontal line, click Ruler. The Diameter, Opacity, Density, and Blur settings work similarly as they do for the retouching tools.