Can You Sell That? A 3-Lane Cheat Sheet for 3D Printed Parts

A kid was selling 3D printed parts at a farmers market. My first thought: I could absolutely hit that kid with a cease and desist. My second thought: most people printing and selling have no idea which of these three lanes they're actually in.

Quick thing before the three lanes: this isn't really a business question. Some people print because watching an idea become a real object is the closest thing to magic they've found. Some are solving a real problem for a real person, a part that didn't exist until they designed it. Some just want to build something their kid remembers. All of that matters whether or not money ever changes hands. If it does turn into a business one day, that's fine too, as long as the people whose work you're building on actually get paid for it. And making your own thing from scratch is the cleanest path there is: nobody sends a cease and desist over your own creativity. Whatever journey brought you here, here's how to tell which lane you're actually in.