<p>Offset printing inks generally consist of pigments, vehicles, and additives, with the vehicle fraction accounting for approximately 30–40% petroleum-based organic solvents. Increasing regulatory pressure and labeling requirements for organic solvent content have driven the development of mineral-oil-free or reduced-solvent ink formulations. In this study, an eco-friendly offset printing ink free from petroleum-based organic solvents was developed by employing vegetable oils conventionally used in varnish systems in combination with a rosin-modified phenol resin. The formulated ink was evaluated in comparison with conventional solvent-based and soybean-oil-based inks with respect to rheological behavior, printability, setting characteristics, gloss, rub resistance, and run stability. The solvent-free ink exhibited basic physical and printing properties comparable to those of conventional inks, while showing a slightly lower viscosity. This reduced viscosity contributed to improved ink transfer behavior under printing conditions, making the formulation suitable for high-speed printing applications. In addition, the solvent-free ink demonstrated stable gloss retention and acceptable run stability without adverse effects on print quality. The results indicate that petroleum-based organic solvents can be effectively replaced by a vegetable-oil-based vehicle system without compromising essential printing performance. The developed ink formulation provides a viable approach for reducing volatile organic compound emissions under the applied laboratory test conditions and potentially reducing workplace exposure to volatile solvents in offset printing processes.</p>