Copper feel PLA based filament MetalFil - Ancient Bronze 2.85mm 1500 gram Natural Composite 3D Printer FilamentFormfutura MetalFil Classic Copper is a composite PLA (polylactic acid) filament that is gravimetrically filled with approximately 80% copper powder. The high copper content in MetalFil Classic Copper makes 3D printed objects nearly indistinguishable from genuine copper casted objects. MetalFil Classic Copper can be post processed with various patina effects. Unique features Very high copper filling of 80% Real copper look, heavyweight, and cold