Footprint of droplets after impact onto paper surfaces with a hydrophobic barrier

We conclude that the final contact area (footprint) could be tuned simply by varying the impact energy of the droplet and vapor deposition time. In contrast to untreated papers, droplets impinging on treated papers impregnate the porous structure but there is no subsequent wicking, i.e. the contact line always pins, which is explained by the interaction of the droplet with fibers of the paper.