These names derived from the fact that Shuinchi were secured by the bakufu with shuinjo (letter stamped with shuin (red stamp)) and Kokuinchi were secured by the daimyo with kokuinjo (letter stamped with kokuin (black stamp)) respectively.
朱印地は幕府より朱色の印が押された朱印状により、黒印地は大名より黒の印が押された黒印状により所領の安堵がなされたので、その名称がある。