With pictures of the Eiffel Tower, ferris wheels, menageries full of animals, 3D pens' packaging gives you the impression that you just dream it up and the pen does the rest. Using one requires a steady hand, patience to let each vector dry, and a respect for the tip, which is hot enough to instantly liquefy plastic. This highly rated (4.8 on Amazon) entry-level pen, compatible with PLA and PCL, will at best refine their fine motor skills and get them interested in 3D printing tech, and at worst is a cool arts and crafts gadget.
