Abstract: The present invention provides a curable composition comprising: (a) a resin composition being liquid at 23° C. and comprising monomers or oligomers or a mixture of monomers and oligomers polymerizable by a ring-opening reaction; (b) an impact modifier containing one or more block copolymers having at least one block composed of methyl methacrylate and (c) one or more polymerization initiators. The curable resin composition can be used for curable coatings per se and in specific for stereolithography and other applications such as three dimensional printing applications where a 3D object is formed.