Packages may be tested for integrity (holes, channel seal leaks, open seals) by inserting a Toluidine Blue Dye solution with a specific viscosity. This method has been shown to detect openings as small as 50 microns. It is suitable for packages made from clear film sealed to non-woven material. It may be used for some clear film/paper packages but care must be taken to separate package failures from wicking.
ASTM F1929 Standard Test Method for Detecting Seal Leaks in Porous Medical Packaging by Dye Penetration