What does a "dual-extruder" FDM printer allow?

A dual-extruder FDM printer is designed to print with two different filaments simultaneously, which is a significant advancement in 3D printing technology. This capability enables the creation of complex parts that can leverage the unique properties of different materials. For instance, you can use one filament for the main structure of the print and a different filament, perhaps a soluble material, for support structures. This allows for easier removal of supports and can improve the quality and complexity of the final print.

Moreover, dual-extrusion can also allow for color mixing, enabling multi-color prints without manual intervention or subsequent post-processing. The versatility provided by dual extruders stands in contrast to single-extruder setups, which are limited to one type of filament at a time and, therefore, do not have the same flexibility in terms of material selection and print complexity. The other choices either misrepresent the capabilities of dual-extruders or misinterpret their functionality, underscoring the unique advantages that such printers offer.