Supima Cotton is basically a genetic cross breeding of the hi-grade Sea Island (Sea Island, Georgia, USA) cotton and Egyptian cotton blends.
This new blend was first grown in Sacaton, Arizona where the Pima Indians were instrumental in growing this new cotton and running all of the field trials. Hence, the name Pima was created for this new blend. Over the years a better grade of cotton was developed and was named Superior Pima. It was a mouthful to say Superior Pima Cotton, and even more to put on a product label. Therefore, like a lot of things the name was shortened to Supima.
Pima is an extra long staple cotton, and is now being grown by other producing nations such as Peru, Australia, and Israel, to meet the world's demand. Therefore the chances are the products you are currently using are of Pima cotton not Supima cotton. The label on the towel will specify if it was made with Supima Cotton.
Before you decide that purchasing Supima Cotton towels is out of you price range. Consider this, The properties of US grown Supima cotton (extra long staple) are above the qualities of Egyptian cotton (long staple cotton). The staple (length) of the cotton is longer, therefore creating a stronger, finer, and higher quality fiber. Shorter cotton staples are used in everyday "run of the mill" textile goods. With this higher quality of cotton you will receive not only a stronger towel, but also a softer one.
Supima cotton towels will launder better than most towels in the marketplace. That is due to this finer grade of cotton that does not lint (excess cotton) up like less expensive towels. Not only do your towels look better out of the dryer, but the dryer doesn't work as much when there is less lint to deal with. That reduces your carbon footprint on the earth. This higher grade of cotton, also dries quicker than lesser qualities of cotton, therefore your towels will dry quicker on your towel rack in the bathroom.
When you shop for towels, look at the labels on the towels to see where the cotton was grown. US farms proudly put their Cotton Cooperative on the label. They want you to know that you are supporting US farms and families. Maybe you can't change out all of your towels today, but next time you are in the market for towels, consider Supima Cotton. Over time the investment will be worth it.