Fountain Pen

Tap it to uncap the pen and write a swirl in wet blue ink.

A fountain pen carries its own ink inside. The ink runs from the barrel through a thin channel called the feed to a split metal nib, and the slit draws it down to the paper by capillary action, the same pull that lets a paper towel soak up water.

This one is made from a detailed 3D model of a real green pen. Tap it and the cap slides off and clicks onto the back end, the nib writes a looping swirl that shines while it is wet and dries darker, and the cap goes back on. With ✋ Hands-on on, pull the cap off the nib yourself and push it onto the back end, where it clicks on turned around, the way people post a cap while they write.