An inkjet printing method includes the steps of: a) printing a first print job by jetting a free radical UV curable white inkjet ink from a white ink print head and one or more free radical UV curable color inkjet inks from one or more other print heads in a UV curable inkjet printer; b) filling the white ink print head in the UV curable inkjet printer with a safeguard liquid including one or more free radical polymerizable monomers; c) printing a second print job employing only the one or more other print heads in the UV curable inkjet printer for jetting one or more free radical UV curable color inkjet inks; d) replacing the safeguard liquid of the white ink print head in the UV curable inkjet printer by UV curable white inkjet ink; and e) printing a third print job by jetting free radical UV curable white inkjet ink from the white ink print head and jetting one or more free radical UV curable color inkjet inks from one or more other print heads in the UV curable inkjet printer.