A method and system for calibrating a device having a first fluid source that ejects a first drop quantity and a second fluid source that ejects a second drop quantity by, for example, printing a pattern having a first portion and a second portion; obtaining a relationship between the first drop quantity and the second drop quantity from the pattern; and adjusting data used to determine quantities of fluid to eject from the first or second fluid sources based on the relationship between the first and second drop quantities. Other embodiments of the invention are directed to a calibration apparatus and system.