Fascia for Decorative Traverse Curtain Rods is available in several styles and diameters. The most common fascia styles are fluted (sometimes called reeded) and smooth. The most common fascia diameters are 1 3/8” and 2 1/4”. Fascia is available in both wood and metal; the example images above are wood, which is most common. Metal fascia is only available in smooth style.
The fascia style and diameter have absolutely no bearing on the strength of the Decorative Traverse Drapery Rod. The fascia is purely decorative and does not add to the strength of the rod. The curtain rod track “does all the work”, so you’re free to choose any fascia style and diameter you want.