1. A method for producing a transform useful for predicting a reflectance value producible by a printer while operating under a predetermined target set of operating conditions using a reflectance value produced by the printer while operating under a predetermined reference set of operating conditions, the printer having a predetermined set of colorants available for deposition on the substrate, the method including the steps of: i) operating a printer under a predetermined reference set of operating conditions to create a first set of K number of samples, each sample being produced using a predetermined colorant or combination of colorants, ii) operating the printer under a predetermined target set of operating conditions to create a second set of K number of samples, each sample in the second set being produced using the same predetermined colorant or combination of colorants used to produce one of the samples in the first set, and iii) measuring actual spectral reflectances for each sample in the first and second sets; wherein the improvement comprises the step of: a) using the actual spectral reflectance for each sample in the first set and the actual spectral reflectance for each sample in the second set, creating a cross-validated, partial-least-squares transform that maps a reflectance from a sample produced under the first set of operating conditions to a reflectance from a sample produced under the target set of operating conditions.