Patent ID: 8462386

Claim:
A method of producing a spot color that matches a hardcopy target color, comprising: measuring the hardcopy target color on an offline instrument to produce a first offline color measurement Lab o1 ; converting the first offline color measurement Lab o1 to a first device-dependent color specification; printing the first device-dependent color specification on a printer comprising an inline color measurement instrument, thereby printing a first printed color; measuring the first printed color on the inline color measurement instrument to produce a first inline color measurement Lab i1 , and measuring the first printed color on the offline instrument to produce a second offline color measurement Lab o2 ; deriving a device-dependent color specification difference from the instrument color difference Lab i1 −Lab o2 ; adding the device-dependent color specification difference to the first device-dependent color specification, thereby updating the device-dependent spot color specification for that spot color; printing the spot color according to the updated device-dependent spot color specification.