Wetness indicators are materials or devices that change color or appearance when they come into contact with moisture. They are commonly used in various applications, such as in diapers, medical supplies, and packaging to signal when an item is wet or has been compromised by moisture. This helps users determine if the product is still effective or safe to use. These indicators can be made from special dyes or chemicals that react to water or humidity. By providing a visual cue, wetness indicators enhance safety and convenience, allowing for better monitoring of products that need to remain dry or sterile.