The J750 PolyJet printer is the newest model of full-color and multi-material 3D printer from Stratasys. Currently, limited information is available about the effects of control factors on thermal glass transition temperature of parts printed by this printer. In this study, the effects of two control factors, printing orientation and layer thickness, on the thermal glass transition temperature (Tg) are investigated. The results suggest that both control factors significantly affect Tg. Specifically, samples printed using the high mix mode have higher elastic moduli than those printed using high quality mode. Larger values of elastic moduli directly lead to a higher thermal glass transition temperature, making the material more effective under relatively extreme temperatures and duress. These results would be valuable to researchers and practitioners who use the Polyjet 3D printer.