My clients had converted their formal dining room to a library with an oak, gate-leg, hunt table, 1920s Belgian wood and leather chairs, and a hand-knotted Iranian rug. The library had three sets of French doors and a pair of windows. All would be covered with gray linen. To preserve as much natural light as possible, I treated the doors as one entity. That is, instead of mounting three separate rods and three sets of finials, I spliced the rods together to make one long one. In total, this allowed the draperies to open more than a foot further. I also maximized the light on the windows by mounting the shades higher on the wall. How high? Enough so that, when raised, the stack of fabric would clear all but a few inches of glass. More math. I attached the shades to black, iron rods that matched the drapery rods. All of these rods, in turn, tied into the existing iron light fixtures and staircase railing.
Source : http://napavalleyregister.com/lifestyles/home-and-garden/columnists/patti-cowger/patti-cowger-s-demystifying-design-a-mix-of-old-and/article_23fad286-1e50-5cf1-ba2b-1af39671e76e.html