The Series 1, like all FFF 3D Printers do not require refills per se like a traditional paper printer.
Series 1 uses filament in spools which you can buy from our webstore or from other vendors (though we can only guarantee the quality of Type A Machines filament). Filament comes in many sizes, shapes, materials, and colors. Series 1 is optimized to use 1.75mm PLA (Polylactic Acid) filament in a wide range of colors. Type A Spools are sold on our webstore from $40.00/kg.
To put it in perspective, A kilogram of 1.75mm PLA, if unraveled would span over 3 and a half football fields. On average, power users go through a kilogram once a month.