D'Addario Chromes have a stainless steel under-winding on a hex core and are wound with flattened stainless steel ribbon wire which is polished to an incredibly smooth surface. After the winding is applied, each string goes through 3 polishing steps. Chromes deliver a distinctive damped but tone-rich sound that only flatwounds can produce. D'Addario Chromes are the world's most popular flatwound strings.