Our tile repair pens contain penetration enhancers, corrosion inhibitors. It can be waterproof and mildew proof, easy to operate, fast drying ink, its use is very simple: 1. Clean the gaps between tiles and keep the gaps between tiles clean and dry. 2. Shake the pen and press the tip until the ink flows out. 3. Press the tip of the pen and draw a line in one direction along the gap between the tiles (if ink oozes, wipe off excess ink. 4. After the completion of construction, avoid contact with water within 48 hours after the completion of construction, and do not bump or scratch within 7 days. And the gap of the tile can be filled to form a complete tile.