(click to embiggen)
Above is a writing sample of Noodler's Black Swan in Australian Roses in the new Noodler's Flex Nib Piston Fill fountain pen. I'll have more thoughts about the pen later, but this is my first attempt at using a flex nib fountain pen, and I think the Black Swan ends up shading quite nicely with it.
Update: Inkophile has a spot-on review of the Noodler's Nib Creaper pen.
Update: Leigh Reyes has a demonstration using the Creaper and the Black Swan ink to draw.