Feathering

Feathering doesn’t pertain so much to the nib as it does the paper a pen writes on. Cheap, poorly made papers are more likely to allow ink to spread more widely than the point of the nib intended. This leads to thicker lines of ink on the page where you can see little spikes of ink spouting for the written line as the ink flows through the fibers. People might want to blame a wet nib for this problem, but it is almost always the fault of poorly made papers. An especially watery ink might also lend a hand in feathering.