Choosing between inside and outside mount affects how your window treatments look, how well they block light, and whether they'll fit your windows at all. Here's everything you need to know.
The product sits inside the window frame, flush with or slightly recessed from the wall.
The product mounts to the wall or trim above (and sometimes beside) the window frame, covering it entirely.
Yes. Many homes use inside mount in rooms with deep frames and outside mount where frames are shallow or where maximum light blocking is needed. Consistency within a single room looks best — mixing mount types within the same sightline can look uneven.
Specifying mount types across a full project? Our trade channels ship pre-measured orders with the correct mount hardware included:
Inside mount fits within the window frame for a clean, built-in look. Outside mount attaches to the wall or trim above the window and covers the entire frame — better for light blocking and hiding imperfections.
Neither is universally better. Inside mount looks sleeker; outside mount blocks more light and hides uneven frames. Choose based on your window depth, aesthetic preference, and light-blocking needs.
Most blinds and shades need 2–4 inches of frame depth. Shutters need 2.5–3.5 inches. Check the manufacturer's specifications for your specific product.
If the frame is significantly out of square (more than 1/4 inch difference across the width), outside mount is usually a better choice to avoid gaps.