JWEI Group sent the E-Leaf iVeni Duo pod kit over for me for review, and I’ve been using it for the past week or so. I’ve ...

In this challenge, I used a Smiggle Spy Pen to draw a full doodle using invisible ink that only appears under UV light! 🔦🖊️ Drawing without seeing the full lines in real time was tricky—but the ...

Rendering in pen and ink; instruction paper ... Pen drawing Publisher Chicago, American School of Correspondence Collection cornell; americana Contributor Cornell University Library Language English ...

The diagnostic pen is designed with mass production in mind. All its parts — from the 3D-printed casing to the replaceable ink reservoir — can be manufactured at low cost.