3M™ Water Contact Indicator Tape 5557 is a 10.2 mil (259 micron) thick tape used to indicate water contact. The tape turns from white to red upon direct water contact.
"Apply 3M™ Water Contact Indicator Tape 5557 to all types of electronics and watch the colour changes permanently from white to red upon contact with water. Our tape detects water and resolves warranty claims accurately and effectively. It minimises false results from high heat and humidity without changing colour and is designed with ingenious different layers, each engineered for a specific purpose. An indicator layer acts to quickly absorb water and draw up colour for visibility in the transparent top film. The transparent PET top film has been designed to be thermal and flexographic with screen print images that show against white backing. This layer protects the indicator layer from soiling and moisture during handling. A polyester liner combines with the indicator layer for die-cutting ease and accuracy. Our own acrylic adhesive, designed to resist UV, chemicals, and temperature bonds with high strength to most substrates, including low surface energy plastics such as polypropylene and powder coatings."