Fig. 14 shows an automotive engine prototype printed by polymer stereolithography illustrated schematically in Fig. 2; with a build chamber of more than 0.5 m2 using a suitable gantry printer. More practical systems might print multiple automotive components in build volumes much greater than 103 m3, and in stark contrast to current commercial laser or electron beam melting systems (Fig. 4) where the build volume is around 0.1 m3 (a factor of 104). Even larger multiple printer systems could conceivably print multi-component aerospace (aircraft) structures and components as illustrated in