This research aims to enhance traditional glass fiber composites by utilizing a mediumreactive unsaturated polyester resin (UPR) synthesized from ortho-phthalic anhydride. The UPR is formulated using unsaturated acids, glycols, and styrene monomers, with the reaction tailored to improve mechanical properties beyond those of standard commercial resins. The liquid resin's properties are evaluated for manufacturing viability, and its solidified form demonstrates superior performance compared to industrial benchmarks. The composite, produced via the hand layup technique, features a reduced resin-to-glass fiber ratio. Mechanical property tests confirm its robustness. Additionally, scanning electron microscopy (SEM) analysis reveals the microstructural characteristics to study the UPR performance.