An epoxy based resin which exhibits good laser ablation and good adherence to a substrate such a copper is provided by adding to the resin a dye or dyes having substantial energy absorption at the emission wave lengths of lasers used to laser ablate the resin. The resin with the dye or dyes included is coated onto a substrate and cured, or laminated onto a substrate in the cured condition. The required openings are formed in the cured film by laser ablation. This allows for the use of optimum techniques to be used to form micro vias.