ProtoPasta, a small company from Washington, USA, with a mission to make 3D printing more interesting and useful, through improved access to unique materials.

Has developed a few very interesting filaments to be used on our desktop 3d printers.

Proto-Pasta are doing that using their special extruder that have developed by themselves that enable them to manufacture PLA filaments with special ingredients inside.
Among their new materials are:
Conductive PLA – PLA with conductive carbon black.
Magnetic Iron PLA – PLA with finely ground iron powder that can rust and attracted by magnets.
Stainless Steel PLA – PLA with finely ground, powdered stainless steel
All ProtoPasta filaments come in the two most common diameters 1.75mm (Flashforge, Makerbot,UP, SeeMeCNC and more) and 2.85mm (Creatbot,Gigabot,Ultimaker and more)
ProtoPasta filaments are new and it will be interesting to see what creators and makers will make with them.