There are several differences between Supima cotton and regular cotton:

1. Cotton Content: Supima cotton requires 100% cotton content, while regular cotton can be considered pure cotton with a cotton content as low as 70%. Supima cotton is a type of pure cotton, but it is of a higher quality and is considered one of the top-tier types of cotton.
2. Characteristics: Supima cotton has many advantages, such as being very soft, warm, and breathable, making it a popular choice for manufacturing close-fitting clothes, bed sheets, and duvet covers. Regular cotton, on the other hand, has slightly lower moisture absorbency and warmth retention, but it is still a common fabric used in clothing.

In conclusion, Supima cotton is a high-quality cotton fabric with superior strength and comfort compared to regular cotton. While both fabrics have their advantages, Supima cotton is the preferred choice for those seeking a more luxurious and comfortable fabric.