We have developed a colour prediction model and an ink-spreading model. The present study aims at confirming the validity of both models for the case of ink-jet prints using cyan, magenta and yellow inks. Our colour prediction model, augmented by the ink-jet spreading model, predicts accurately the reflection spectra of halftoned samples printed on an HP printer and on an Epson printer. For each printer, the reflection spectra of 125 samples uniformly distributed in the CMY colour cube were computed. The average prediction error between measured and predicted spectra is about ΔE = 2.5 in CIELAB. The model requires the estimation of a set of parameters which are deduced from a small set of measured samples. Such a model simplifies the calibration of ink-jet printers, as well as their recalibrations when ink or paper is changed.