Spectra AD Markers are extremely versatile, featuring dual-ended tips with a flexible brush tip on one side and an innovative Tri-nib on the other. These alcohol-based markers dry fast, are permanent, and are non-toxic. The AD Marker signature Tri-nib offers three line widths fine, medium and broad with a twist of the wrist. They can be used with the Spectra AD Blender to create gradations, to blend and lighten color. Spectra AD Markers can also be used with traditional xylene-based markers.