The two standard diameter sizes for filament are 1.75mm or 3mm, which is made from either polyhydroxyalkanoate or polylactate and can, come in different colors. It became soft and moldable when heated and return to a solid when cooled. It is commonly used for printing of 3D prototypes. The smell of 3D Printer Filament while printing will vary largely from manufacturer to manufacturer based in large part on how much degradation occurred during production. Filament with a smaller diameter can be heated faster so can print faster. Being smaller, it is so more flexible and can be coiled more tightly and turn sharpener corners.