Fluorescent penetrant inspection (FPI) is a nondestructive means to do inspection of materials and parts for indications of surface discontinuities and imperfections.  FPI subjects are cleaned, exposed to fluorescent dye penetrant, developed, rinsed, then inspected under ultraviolet light to reveal areas where the dye has remained in an indication or surface discontinuity.  ETI INC. inspectors are certified by the American Society for Nondestructive Testing to perform up to a Level 4 High sensitivity FPI.