"Shading" is a property of a fountain pen ink wherein the ink, when applied to paper, appears to show multiple, discrete shades of the ink color. In a flex pen, this can produce dazzling effects when well controlled. This property is apparent in many, but not all fountain pen ink.
Very prominent in: Noodler's Apache Sunset, J. Herbin Lie de Thé, Diamine Ancient Copper, Caran D'Ache "Storm" to name but a few.
How to adjust a Desiderata flex nib for more shading:
- For more shading, you want to ever-so-slightly starve the ink flow to the nib point; to achieve this, when aligning your clean nib with the feed, shift the nib forward, point away from the ink channel a little bit. Adjust as necessary to get closer to the results you want.
- For less shading (more consistent flow), you want uninterrupted ink flow to the nib point; to achieve this, align as described here in the manual under point 2, "Tuning", or, if necessary to achieve more flow, slide the nib point up onto the ink channel further than before.