Abstract: Described herein is a photocurable resin composition for stereolithography comprising (a) a photocurable component, liquid at room temperature and comprising a photopolymerizable substance selected from monomers, oligomers, dendrimers and polymers and mixtures thereof, (b) at least one photoinitiator compound, and (c) at least one photoactivated color changing compound. The color changing compound can be adapted to go from essentially colorless to a given color, one given color to another or from a given color to colorless. Optionally, the resin composition will also contain component (d), namely at least one reactive silsesquioxanes (POSS).