Spectra AD® Markers are alcohol-based markers that are ideal for art and design projects. Spectra AD Markers are extremely versatile, featuring dual-ended tips with a flexible brush nib on one side and a unique tri-nib on the other. The AD Marker signature Tri-nib offers three line widths – fine, medium, and broad – with the twist of the wrist. The nibs are removable and replaceable, and the markers are refillable. Colors dry fast, are permanent, non-toxic, and are low odor. They can be used with the Spectra AD Blender Marker to create gradations, to blend and lighten color, and to mix with other colors to create something truly unique! Spectra AD Markers can be used with traditional xylene-based AD Markers. For best results, keep finished works out of direct sunlight.