A solder mask ink composition is disclosed. The solder mask ink composition includes an epoxy resin; a solvent in an amount of at least 20% by weight relative to the total weight of the solder mask ink composition; and optionally a non-ionic surfactant. The ink composition has a viscosity that is less than 1000 cps at a shear rate of 10 s−1 and greater than 30 cps at a shear rate of 495 s−1 and a temperature of 25° C.