These Oeko-tex certified cotton sweatpants survived our child in flawless condition. The double layered fabric on the knees may have played a part, or the fact that we used them mostly for dance classes and not for outdoor play. He took tap and ballet last year, so very little time on the ground overall. In addition to their like new condition, these have been washed only in Molly's Suds nontoxic detergent, so they are harmful chemical-free through and through. These also have a functional drawstring and three pockets, two of which are zip-up hand pockets. Combine with other items in our closet and make a bundle for an even better deal. Thank you!