Bite tugs are also much better than solid hard rubber balls on strings. When a young dog is accidentally hit in the head with a hard rubber ball he will loose drive. When the same dog gets hit by a tug he ignores the situation and continues to chase in drive. I choose to have my tugs made from this fabric to get as much durability as possible without un-necessary wear on the dog's teeth. It's a balancing act.
Jute wears too easily and some other fabrics that last a little longer are too hard on the teeth.
My tugs are not designed as chew toys for a dog. They are training aides. Of course if you make the mistake of letting your dog carry it off and chew on it for 30 minutes you will be ordering a new tug. The tugs vary in length and diameter, which one you use will vary according to the goal of your training. Drive building in adult dogs is always done with the smallest tug.