Fabric Composition Matters: Our bags are made of TUV certified food grade polyester. Fine mesh polyester not only filters well, but also allows adequate drainage. High-efficiency filtration: Some hairy tissues absorb and retain the tips of the particles, which cannot be cleaned very well. Our bags are very soft and there are no loose fibers under the microscope. Choose our bags to filter all small particles to enhance efficiency, clarity and drainage performance. Safe to Boil: The polyester material of our brew bag has a heat resistance of 248℉ and can withstand boiling, which will be your last preparation bag. Durable:We use durable polyester fibers, which are strong, stretch and shrink resistant, and wear-resistant. Each stitch has been reinforced and is not prone to tearing or breaking. The reinforced double-seam edge can accommodate a variety of grains. Quick and Simple Cleaning: The fabric is free of loose fibers. Cleaning is very easy. It will dry quickly when hanging, because it does not absorb water. The seams are outside and there are no particles in the bag.