I worked on a project where we received promo materials for Grav Labs and a few of these pens were sent along. I wrote with that pen on every single thing I needed to write with until sadly the ink died. I've been desperate to get another one ever since. I still have the dead pen in my pen cup to remind me. Decided to check in today and I'm THRILLED to learn that I can now purchase a set. Thank you Grav Labs!!