A fabrication method and the optical characteristics of a polymer-dispersed liquid crystal (PDLC) system based on polyvinyl butyral (PVB) as the polymer matrix and 4-n-pentyl-4′-cyanobiphenyl (5CB) as the liquid crystal are proposed. PDLC films were prepared using the thermal-induced phase separation (TIPS) method with various compositions of the two components. Detailed investigations employing polarized optical microscopy and differential scanning calorimetry were carried out to assess the correlation between the composite composition and PDLC formation. It was found that PVB and 4-n-pentyl-4'-cyanobiphenyl (5CB) are partially miscible, with a maximum solubility limit of 42.8%. The presented thermal results and analysis expand the current understanding of TIPS-based PDLC formation. The use of PVB as a polymer matrix in PDLC systems opens up new possibilities in PDLC design due to the superior performance of PVB compared to other polymers commonly used in PDLC systems. It is demonstrated that PVB can serve as an effective polymer matrix for the formation of PDLC systems.