Gray balance calibration of an imaging system

Apparatus comprising:

• a calibration user interface configured to cause a display, on a display screen, of calibration instructions to a user and configured to accept, via interaction with an input interface, a calibration adjustment value;
• computer memory;
• a processor;
• a given imaging device including a predetermined print engine capable of being calibrated;
• a calibration sheet;
• the calibration sheet including at least one visible calibration reference region including a given mix of one or more pre-selected reference colorants printed in the at least one calibration reference region on the calibration sheet, the one or more pre-selected reference colorants having been previously printed on the printable calibration sheet using a different imaging device that is separate and different than the given imaging device and that has the same print engine and same print technology as the given imaging device;
• and
• the calibration sheet including one or more freshly printable target regions on the calibration sheet, wherein the given imaging device is configured to enter into a calibration mode, and wherein the given imaging device, when in the calibration mode, is configured to freshly print a mix of colorants corresponding to the one or more pre-selected reference colorants onto at least one of the one or more target regions.

A method comprising:

• providing a given imaging device including a predetermined print engine capable of being calibrated;
• providing a calibration sheet;
• the calibration sheet including at least one visible calibration reference region including a given mix of one or more pre-selected reference colorants printed in the at least one calibration reference region on the calibration sheet, the one or more pre-selected reference colorants having been previously printed on the printable calibration sheet using a different imaging device that is separate and different than the given imaging device and that has the same print engine and same print technology as the given imaging device;
• and
• the calibration sheet including one or more freshly printable target regions on the printable calibration sheet, wherein the given imaging device is configured to enter into a calibration mode, and wherein the given imaging device, when in the calibration mode, is configured to freshly print a mix of colorants corresponding to the one or more pre-selected reference colorants onto at least one of the one or more target regions.