This work describes the development and characterization of mechanical flexible epoxy resins based on epoxidized vegetable oils (EVO) and sebacic acid. Different oil types (linseed oil, hempseed oil, and soybean oil) with varying epoxy equivalent weight (EEW) were used. Formulation and processing parameters were systematically optimized by differential scanning calorimetry and Fourier-transform infrared spectroscopy. The effect of the EVO type and EEW on thermo-mechanical and mechanical properties were investigated by dynamic mechanical analysis and tensile tests at different temperatures. The EVO type had a strong effect on the thermo-mechanical and mechanical properties of the resin. However, for the investigated commercial epoxidized linseed oils, the EEW had no effect on these properties. With epoxidized linseed oil the highest Tg and the best mechanical properties (highest tensile strength and toughness) were achieved.