Sketch pens—often seen as simple tools for coloring and line work—are vastly underestimated in the world of art. Most people think of them as basic coloring instruments for school projects or casual doodling. But with the right techniques and understanding of the medium, sketch pens can go far beyond their perceived limitations. One of the most exciting frontiers for sketch pen users is shading, layering, and blending—techniques more commonly associated with paints or colored pencils.