Whether you like it or not, technology is ubiquitous (as are the people who make it). There is no escaping the brilliance and the evil (take your pick) of technology. Not even the artists.
To be honest, 3D printing/drawing has been one of many evolving technologies that we haven’t been able to fully understand. Thank God for YouTube. Colorful artist and YouTuber The Official Rainbow Girl posted this highly illustrative video of herself doodling the Golden Gate Bridge, with the actual Golden Gate Bridge in the background, using a 3D pen.
So now we get it: the pen uses plastic which then quickly melts causing an artist’s drawing to pop off the page. It’s hard to explain, so take a look: