What is the blackest easily available marker?

The blackest easily available marker is often considered to be the Posca Paint Marker or the Sharpie Black Oil-Based Paint Marker. These markers produce a deep, rich black color with Excellent opacity and coverage on various surfaces. For art applications, the Black 3.0 acrylic paint, developed by Stuart Semple, is also known for its extreme blackness, though it may not be a traditional marker.