How do I determine if a rod is strong enough for blackout drapes, and how wide should I mount it?

Most standard 1-inch diameter rods support **20–30 lbs**. For blackout or velvet drapes, ensure you use a center support bracket for spans over 60 inches. For mounting width, extend the rod **4–6 inches beyond the window frame** on each side; this "stack back" allows the curtains to clear the glass when open, maximizing natural light and making the window appear larger. This standard mounting rule, frequently cited by interior designers on The Spruce, creates the illusion of a more expansive and grand window treatment.