"30mm Cotton" refers to cotton fibers with a diameter of 30 millimeters. This type of cotton is known for its length, softness, and versatility. It is commonly used in various applications such as textile manufacturing, where the longer fibers contribute to the production of high-quality and durable fabrics. The 30mm cotton is favored for its ability to create smooth and comfortable textiles, making it a popular choice in the fashion and garment industry.