If you have ever drafted by hand for work or pleasure, you know that straight lines are hard to sketch or trace by pen or pencil without something as your guide – and laying down the ruler, triangle or square each time takes, well, time. What if you could just snap something onto your drawing tool instead?

But this concept goes beyond simple enabling linear effects Рfrom drafting to simply underlining more neatly in books Рit is envisioned by product designer Giha Woo as a way to measure while you draw as well, and display the results in realtime on a digital readout.

These days there may not seem much need since computers can draft for you, but any creative person knows there is something about putting pen to paper (or stylus to pad, at the very least) that gives you a more visceral connection to your creation.