A nib for a valve-free free ink writing felt pen including a first end configured to deliver ink to a writing support and second end, opposite the first end, configured to be inserted in a nib receiving part of the valve-free free ink writing felt pen, the first end and the second end defining an axial direction of the nib, the nib having an external surface configured to cooperate with an internal surface of the nib receiving part, the external surface being configured to allow intake of air from the outside of a free ink tank, the valve-free free ink writing felt pen into the free ink tank and avoid ink leakage outside the free ink tank when cooperating with the internal surface of the nib receiving part. A valve-free free ink writing felt pen including a nib.