Example of the composite spectra generated with PRISMA for two spaxels in a face-on galaxy of our CIELO sample. Left panel: Stellar mass-weighted distribution of a given galaxy, where two spaxels are highlighted in red and blue. The red spaxel contains only stellar populations older than 10 Myr, whereas the blue spaxel contains both old and younger stellar populations. Right panels: Corresponding spectra obtained with PRISMA from each of these spaxels (red and blue spectra, respectively). Additionally, the inset plot shows the old, young and nebular contributions (orange, cyan, and violet, respectively) that compose the total spectrum of the blue spaxel. These spectra were not attenuated by ISM dust along the LoS.