A curable ink composition for forming a three-dimensional (3D) object via a digital additive manufacturing system is provided. The composition may comprise greater than about 30 weight % of one or more oligomers, at least two monomers comprising a lowest viscosity monomer and a highest viscosity monomer, one or more photoinitiators, and optionally, one or more additives. The ratio of the weight % of the total amount of oligomers to the weight % of the total amount of monomers may be at least about 0.5 and the ratio of the weight % of the lowest viscosity monomer to the weight % of the highest viscosity monomer may be at least about 5.