The Chartpak Spectra AD Marker, Tri-Nib and Brush Dual-Tip, 12 Assorted Basic Color set in plastic case, contains low odor, Alcohol-based markers that are ideal for art and design. These markers in 12 brilliant colors feature a Dual-tip with 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.