Making new curtains for my RV and they a sewn on strip to hang from the hooks. Anyone know what this strip of material might be called and when to find it?
The braid-looking stuff? It looks like a variation of upholstery trim. Kinda like ball-fringe except with loops instead of Pom-poms. You might be able to achieve a similar effect via vertical buttonholes in your curtain at the desired increments. Fabric shower curtains sometimes sport buttonholes to accommodate shower curtain hooks. Grommets are another option.
You could definitely peruse the upholstery trim selection at Joann or hobby lobby or an upholstery supply place like Calico Corner or Childress fabrics. I think there is also an option that is essentially twill tape with plastic rings attached at regular increments.