The Chartpak Spectra Ad marker, tri-nib and brush Dual-tip, true Blue, is a low odor, Alcohol-based marker that is ideal for art and design. Available in 96 brilliant colors, this dual tip marker features tri-nib on one end for fine, medium and broad lines and a flexible brush nib on the other end. With fast drying, permanent and non-toxic color, these markers have a comfortable, ergonomically-shaped barrel that does not roll away. Use with Chartpak Spectra Ad blender marker (sold separately) to create gradations, to blend and to lighten color.