Every custom blind order starts at the same fork in the road: inside mount vs outside mount blinds. Get it right and everything after it is easy. Get it wrong and you spend the next five years looking at either a light leak you can't unsee or a beautiful window casing you've completely covered up.
Most of the time you get to choose, and the choice is about looks. Some of the time your window quietly makes the decision for you — a shallow frame, a crank handle, a tile return — and the trick is knowing which of those two situations you're in. That takes about thirty seconds.
Below is a verdict for every common case. Not "it depends" — an actual answer, plus what we'd do if it were our window.
Inside Mount vs Outside Mount Blinds: The 30-Second Answer
Choose inside mount if your window frame has enough flat depth for the brackets and you like a clean, recessed, built-in look. The shade sits inside the opening, your trim stays visible, and nothing goes into your wall.
Choose outside mount if you want maximum darkness, if your frame is shallow, if the window is out of square, or if the frame itself is something you'd rather hide. The shade mounts on the wall or trim above the opening and covers everything behind it.
If you're genuinely torn: default to inside mount everywhere except the bedroom. Inside looks better in most rooms, and the bedroom is the one place where the last few percent of darkness is worth more than the tailored look.
That's the rule of thumb. The rest of this page is the fine print worth knowing before you order.
Inside Mount: The Built-In Look
An inside-mount shade drops into the window recess, so the frame stays on show and the whole thing reads as part of the architecture rather than something added later. If you have decent trim — a deep sill, a chunky casing, anything you'd point out to a visitor — inside mount is how you keep it.
The other quiet advantage is that nothing gets drilled into your wall. The brackets go into the window frame itself, which means smaller holes in a less precious surface.
How much depth do you actually need?
Enough flat depth inside the frame for the brackets to sit properly. Our measuring guide puts the screening number at a minimum of about 2 inches (roughly 50 mm), and that's the figure to use as of August 2026 when you're standing at the window with a tape measure deciding whether inside mount is even on the table.
Treat 2 inches as the screening test, not the final answer. Depth requirements differ between systems, and a cassette or valance needs more room than a bare roller — so check the depth requirement on the specific product page for the shade you're actually ordering. If your frame comes up short, that's not a problem to solve, it's just a decision made for you: outside mount.
The light gaps, honestly
Inside mounts have light gaps. Every inside mount, every brand, ours included. The shade has to be slightly narrower than the opening or it would jam, so we take a small clearance deduction — about 1/8" — off your width before we cut. That clearance shows up as a thin bright line down each side when the sun is directly behind the shade.
In a living room or a kitchen you'll never think about it. In a bedroom at 6am in June, you will. This single fact is why the bedroom verdict below goes the way it does.
The other trade-off
Inside mount is the less forgiving measurement. You're fitting a made-to-measure panel into a fixed opening, so out-of-square frames and bowed sills show up. Our factory handles the deductions — you send the exact opening and we do the math — but the opening still has to be square enough to accept a rectangle. Full method in how to measure for each mount.
Outside Mount: The Coverage Play
An outside-mount shade hangs on the wall or trim above the window and overlaps the opening on every side. It is the more forgiving of the two mounts in almost every way, and it is the one people underrate.
It kills the side light gaps, because there's no recess for light to sneak around. It makes a small window look bigger, because you control where the top and the edges land. It forgives an out-of-square opening entirely, because the shade never has to fit into anything. And it covers a tired or mismatched frame completely.
How much overlap
We recommend at least 1.5 to 3 inches of overlap per side — 3 to 6 inches wider than the opening in total — for proper light control and privacy (measuring guide, as of August 2026). For height, you need roughly 2 inches of flat surface above the frame for the brackets, and then you measure down to wherever you want the bottom of the shade to sit. Mount higher than you think: taking the shade up towards the ceiling is the cheapest way to make a window look taller than it is.
On an outside mount there are no deductions at all. You give us the finished size you want to see on the wall and we build exactly that.
What you give up
Trim. If the casing is the nicest thing about the window, an outside mount hides it. You also need anchors in the wall or ceiling rather than the frame, which is a bigger commitment — worth a look at the installation guide before you order if you're doing it yourself.
When You Have No Choice
Some windows decide for you. If any of these describe yours, stop weighing looks and take the verdict.
- Shallow frames, or no usable frame at all. Can't hit the depth for brackets? Outside mount. There's no workaround worth attempting here.
- Cranks and handles in the way. Casement windows with a crank sticking into the opening are the classic case. Outside mount — or, if you have depth to spare and want to stay inside, a reverse roll hangs the fabric off the back of the roller so it clears the obstruction.
- Tile, stone or quartz returns. Uneven or stepped sills make an inside fit fussy. Outside mount is more forgiving and looks more deliberate.
- Older, out-of-square openings. If the width at the top and bottom disagree by more than a hair, outside mount and stop measuring three times.
- Blackout is the whole point. Outside mount. An inside mount with a blackout fabric still has clearance gaps at the sides; the fabric goes dark, the edges don't.
- Patio and French doors. Handles protrude, and the shade needs to clear them. Outside mount, mounted high and wide.
Room-by-Room Verdicts
Bedrooms — outside mount. Sleep beats styling. The overlap is what actually removes the side light, and it's the difference between a dark room and a dim one.
Living rooms — inside mount if the depth allows. This is where the built-in look pays off, and where a bright edge at the sides costs you nothing. If you're doing a whole wall of windows, inside mount keeps the rhythm of the frames visible.
Kitchens and bathrooms — inside mount. Keeping the shade inside the recess pulls it back from splashes, taps and the edge of the counter, and it's easier to wipe around. The exception is a window right behind a sink where the sill collects water — go outside and mount high.
Rentals — inside mount, usually. The brackets go into the window frame rather than your wall, which is the smaller hole in the less contentious surface. Check your lease before you drill either way, and take the shade with you when you go: it's yours.
Home offices and media rooms — outside mount. Same logic as bedrooms, but the enemy is screen glare rather than sunrise.
Check your depth, then take the numbers with how to measure for each mount.
Frequently Asked Questions
Is inside or outside mount better for blinds?
Inside mount looks better in most rooms — it shows off your trim and reads as built in. Outside mount performs better: more darkness, no side gaps, and it forgives windows that aren't square. Inside for looks, outside for coverage.
How much depth do inside mount blinds need?
Plan on a minimum of about 2 inches (roughly 50 mm) of flat depth inside the frame for the brackets, and more if you've chosen a cassette or valance. Check the depth requirement on the product page for the specific shade before ordering — the screening number gets you to the shortlist, the product page gives you the answer.
Do outside mount blinds block more light?
Yes. An inside-mount shade has to be slightly narrower than the opening to clear it, so a thin gap runs down each side. An outside mount overlaps the opening by 1.5 to 3 inches per side, so there's no gap to leak through.
Can you mount blinds on the ceiling?
On the right system, yes. Our compact square cassette uses snap-on brackets designed for wall or ceiling mounting, and the Snug universal bracket installs in either application. Ceiling mounting is a good move for floor-to-ceiling glass or when there's no usable wall above the frame.
Should bedroom blinds be outside mount?
If darkness matters, yes. Blackout fabric on an inside mount still leaves the clearance gaps at the sides, and those edges are what wake you up. Outside mount with generous overlap is the version that actually blacks out.
Pick Your Mount, Then Measure Once
Inside if you have the depth and you love the trim. Outside if you want the room dark, the window bigger, or the frame gone. When your window has a shallow recess, a crank, a stone sill or a stubborn out-of-square opening, it has already chosen for you — and outside mount is a genuinely good outcome, not a consolation prize.
Pick your mount, grab the measuring guide, and your windows are 60 seconds from a price.
Shop Now — or order free samples first if you want to see the fabric in your own light, and get a price in about 60 seconds when you're ready.