A resin solution usable for forming a protection layer, including an organic solvent and a resol resin. The resin solution may further include any combination of a cross-linking agene or agent(s), a photo active compound (PAC) or compounds(s), and/or development accelerator or accelerator(s) a method forming a cured resin layer, including applying a resin solution, including a resol resin, directly or indirectly on a substrate and hard baking the resin solution to form the cured resin layer. The resin solution may include a resol resin and/or a novolac resin.