How is 3D printing done and what’s the best thing you have made

Question: How is 3D printing done and what's the best thing you have made
- Keywords:
  invention,
  material,
  preference,
  technology
Asked by Rachel F to Colin on 11 Nov 2014.
- Colin Keogh answered on 11 Nov 2014:
  
  It basically melts plastic wire and builds any object layer by layer until you have the final product. This link explains it well
  http://rack.0.mshcdn.com/media/ZgkyMDEyLzA4LzAxLzE3XzM3XzAzXzc3Ml9maWxlCnAJdGh1bWIJMTIwMHg5NjAwPg/cdd038eb
  
  The best thing i have printed is a prosthetic hand for a little girl who had lost her fingers. We made her a fully functioning hand with moving fingers for less than 5 euros (most medical prosthetic hands cost more than 5,000 euros). As she grows up and gets bigger, we can make her bigger version of the hand, and then print new parts if any get broken.

Question: How is 3D printing done and what's the best thing you have made