Each pen can be filled with pretty much any liquid ink or water-based paint

Street Killer Ink or the Full Metal Paint

covering both background shading and tighter detail work without switching tools

The stickers are made of ultra-thin vinyl which makes them practically unremovable once they have been put up

molotow blackliner pen round tip Idwrap Each pen can be filledThe Molotow's Blackliner pens are filled with black permanent pigment ink and are perfect for drawing outlines and details. The ink is waterproof and is classified as "archival ink" with high lightfastness. Like most of Molotow's products, these are also made in Germany.