Make sure to include a purge tower and adjust your purge volumes to ensure a clean separation of white and black.
Print on the back side of the skull with supports.
3MF file for Bambu Studio included
Currently scaled at 10x. Shrink as needed.
NOTE: Unless you REALLY want to use two materials, I'd use this other design instead - it's much faster and the end result is nearly identical: https://www.printables.com/model/621121-easy-print-mega-lego-skeleton-skull
The author remixed this model.
Merged multiple files to create a grouped STL file for a multi material printer.