If one has a multi-material printer there are more options than simply printing in different colors of the same filament. [Thomas Sanladerer] explores combinations of different filaments in a fantastic article that covers not just which materials make good removable support interfaces, but also which ones stick to each other well enough together to make a multi-material print feasible. He tested an array of PLA, PETG, ASA, ABS, and Flex filaments with each in both top (printed object) and bottom (support) roles.