AbstractInk vehicles were prepared by the polymerization of vegetable oils. By controlling the polymerization conditions, the desired viscosity, color and molecular weight could be achieved for a variety of vegetable oils with a broad range of iodine values and fatty acid compositions. The effect of temperature and catalyst on polymerization rates were evaluated, and polymerization rate constants were calculated. Of the oils tested, the polymerization rate constant of safflower oil was the highest, followed by soybean, sunflower, cottonseed and canola oils in decreasing order. Use of a catalyst shortened the heating time by about 25–50% or lowered the polymerization temperature requirement by 25–30°C.