A nib for a calligraphic dip pen includes a first inner plate with a first inner plate point end, a second inner plate with a second inner plate point end, and a core with a core top end. The first inner plate and said second inner plate are affixed to the core top end. The first inner plate and the second inner plate are bent toward an axial line of the core such that the first inner plate point end and the second inner plate point end are in contact. The nib for a calligraphic dip pen further includes a spacer plate positioned against either the first inner plate or the second inner plate. The spacer plate includes a spacer plate point end positioned in contact with both the first inner plate and the second inner plate.

A double-head marker pen includes a first penholder, a second penholder and a connecting tube; one end of the first penholder is formed with a first pen head, and one end of the second penholder is formed with a second pen head; and an end of the first penholder away from the first pen head is detachably connected with an end of the second penholder away from the second pen head by the connecting tube.