Parallel Pen. This quite recent calligraphic fountain pen has a nib made of two identical blades of thin steel, square cut, with the ink coming through but never bleeding. It's very funny to have two of these tools containing different colours "kiss" themselves: the inks then mix due to capillarity and will give surprising lines. The Parallel Pen comes in four different sizes, each plastic box with two cartridges (black and red) and a converter to wash inside the pen.
