Doggie Design has incorporated style and safety in their new Dog Harness Tank Shirts! All slogans are machine embroidered on high quality cotton knit fabric and are machine washable. This dog harness tank shirt has nylon webbing underneath the shirt, one for the upper chest area and one that goes around the tummy. This is much more secure and safe for your dog and you get the added benefit of being able to show off your dog in their designer dog clothing, instead of having to put a harness on over their clothing. Sizing Information: To determine your dog's size, measure the girth arount the neck and chest. The chest measurement is critical, especially in larger breeds that have a much deeper chest. Please go up one size for dogs with very thick coats or if you dog is on the border limit.