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 surface roughness of parts printed by this printer. In this study, the effects of two control factors, finish type and Shore hardness, on surface roughness are investigated. The results suggest that both control factors significantly affect surface roughness. Specifically, samples printed with glossy finish have lower surface roughness than those with matte finish, and larger value of Shore hardness leads to lower surface roughness. These results would be valuable to researchers and practitioners who use the J750 3D printer.