A radiation curable gel ink spreading system includes a print head for jetting radiation curable gel ink onto a front side of a substrate, a heated re-flow drum for contacting a back side of the substrate to heat the gel ink and cause the ink to re-flow, and at least one radiation source that irradiates the heated ink to reduce or stop re-flow. A re-flow drum temperature, amount of radiation emission per unit time, radiation source location including a substrate wrap angle with respect to the re-flow drum and/or the radiation source, a distance between a re-flow zone start and the radiation source, and a gap distance between the radiation source and the substrate, and a process speed or substrate translation speed are adjustable for achieving desired spreading characteristics.