Remember how Nokia used to offer removable plastic back covers in different colours for its phones? The Lumia 820 sees a return to those simpler days-- if in DIY 3D printing form. 

Customers with access to a 3D printer can get all the files and documentation required ("3D templates, case specs, recommended materials and best practices") in what Nokia calls the "3D Printing Development Kit" (3DK). 

Users without such equipment can, of course, just buy Nokia-made back covers in different colours, as well as covers offering ruggedised or wireless charging capabilities. 

Nokia first introduced customisation to its phones around 15 years ago with the Nokia 5110 (aka 5120 in America). How times change, right?

Go Everything You Need to Know About the Lumia 820 and 3D Printing