A true collectors item

and they trace lines that are 1 mm in width

Tip: Flexible high-elasticity nylon fiber brush — form-stable shape retention

The tip traces lines that are 2 - 5 mm wide

Cave (Copenhagen)

flux industrial mop fx mop 200i flip cap NER A true collectors itemClassic shoe polish mop filled with black FLUX FX. INK. The round tip leaves thick creamy lines, and you can squeeze the body of the marker to get even more ink out. The FLUX ink is alcohol based, so called penetrating ink that absorbs into the surface. The tip is 2 cm in diameter and it is made from foam. Best for use on smoother surfaces. The marker is refillable, and extra tips can be purchased separately.