Our tile grout pen contains amorphous silicon and aluminum hydroxide. It can protect the gaps between tiles, keeping them as bright as new. After application, it can be exposed to water for up to 60 minutes and is waterproof, stain-resistant, and does not fade. Its usage is very simple: clean and dry the substrate surface, rub and apply the ink, draw along the gaps, avoid contact with water, and let it dry for about 1 hour. It also ensures long-lasting effects.