Underwater writing technique lets you draw patterns in liquids

Writing on solid materials, like parchment or paper, is possible because the ink binds to the surface and remains undisturbed. But in a liquid, particles are constantly moving around, and ink quickly disperses – until now.

Thomas Palberg at Johannes Gutenberg University Mainz in Germany and his colleagues have used a resin bead to draw lines and patterns in water containing ink particles. It works because the bead produces paths of low acidity through the water that attract the ink.

To move the bead along specific …