Uni-ball eye, 0.7 (fine) in black color. Decent pen for writing, but because it is liquid, the 0.7 appears much bolder on most papers. Works great for drawing and painting, a big advantage is that the ink is waterproof! Be careful, the colored inks from the same series (e.g. purple) are NOT waterproof. Only the black, blue, and red are waterproof.