Nail Tek Nails. Nail Tek base coat. NailTek Foundation II is a ridge filling base coat for normal nails. Designed to strengthen your nails while concealing defects from daily exposure to detergents and environmental stresses, this Foundation formula goes on clear beneath your polish. An excellent base coat that not only allows you to apply nail polish evenly, but gives your nails incredible protection, NailTek Foundation II is the perfect start to every manicure.