Feathering

Feathering happens when ink spreads out along the fibers of a paper instead of staying within the crisp lines the pen laid down, creating a soft, fuzzy or blurred edge instead of a clean stroke. It is most visible on thin, uncoated or highly absorbent paper, where ink has less resistance and wicks sideways as it soaks in rather than drying where it landed.

The severity of feathering depends on a combination of paper fiber structure and sizing, which is a coating that controls how much liquid a sheet absorbs, along with the ink's own viscosity and drying speed. Thinner, more watery inks tend to feather more than thicker, more viscous ones, and pressing hard enough to deposit extra ink increases the risk even on decent paper.

To reduce feathering, choose paper marketed for calligraphy, fountain pens or marker use, since these typically have heavier sizing than standard printer paper. A common mistake is blaming the pen or ink first when the paper is usually the bigger factor; testing the same ink on a few different papers quickly reveals whether the problem is the surface. Letting ink dry fully before touching the page also prevents smudging that can look similar to feathering.