Embodiments in accordance with the present invention encompass compositions containing a latent catalyst and a compound capable of generating a Bronsted acid with a counterion capable of coordinating and activating the latent catalyst along with one or more monomers which undergo ring open metathesis polymerization (ROMP) when said composition is exposed to a suitable radiation to form a three-dimensional (3D) object. The catalyst system employed therein can be sensitive to oxygen and thus inhibits polymerization in ambient atmospheric conditions. The three-dimensional objects made by this process exhibits improved mechanical properties, particularly, high distortion temperature, impact strength, elongation to break, among others. Accordingly, compositions of this invention are useful as 3D inkjet materials for forming high impact strength objects of various sizes with microscale features lower than 100 microns, among various other uses.