Inline color tracking for graded 3D printing presents a novel method to track the color of heterogeneous extruded materials on the print path using the robot's internal and external joints with timestamps.

This approach offers a method to monitor the changes in material type since various materials with distinct properties in multi-material 3D printing have varying extrusion speeds, and the juxtaposition of the fabrication model and the monitoring model allows for more precise grading in 3D printing and adjustments to 3D printing settings accordingly.