Ralph Nader has a problem. After using his beloved Paper Mate Flair felt-tipped pens for more than 30 years, Nader noticed a change: His pens have been drying out faster than ever. He reached out ...

A felt-tipped pen contains lots of hidden colors. In this experiment, youʼll flush them out. The ink in a dark felt-tipped pen is a mixture of different colors. When the liquid comes into contact with ...

[Mike Davey] built this one using servo motors, a Parallax Propeller, felt-tipped pen, and 1000 feet of film leader. The machine writes characters to the leader, reads them using a grayscale ...