Fluo Dye Penetrant is a widely applied and low-cost inspection method used to locate surface-breaking defects in all non-porous materials (metals, plastics, or ceramics). The penetrant may be applied to all non-ferrous materials and ferrous materials, although for ferrous components magnetic-particle inspection is often used instead for its subsurface detection capability.

>It is a water-washable fluorescent penetrant designed for dip tank use with good self-developing properties.