Every custom blind order asks one question before it asks about color or fabric: does the blind sit inside the window opening or on the wall around it. Picking inside mount blinds vs outside mount blinds decides the number you write on the order form, and the two mounts are measured in opposite directions. One of them is adjusted for you after you submit it, and you never see by how much.
This is an independent editorial review. SelectBlinds did not review or approve this article.
The certification described below is a voluntary industry program rather than a law or a building code. A manufacturer chooses whether to submit a product to it, the testing is carried out by named outside laboratories, and nothing in it governs how a blind is fitted once it reaches a home.
Reading inside mount blinds vs outside mount blinds in one table
The table below is about measurement and fit rather than about looks, because fit is the part a custom order cannot undo.
| What differs | Inside mount | Outside mount |
|---|---|---|
| Where the headrail sits | Within the window opening | On the wall or trim above it |
| What you measure | The opening itself, exactly | The area you want covered, plus overlap |
| Who adjusts the figure | The factory, after you order | You, before you order |
| Depth requirement | Set per product, published on each product page | None in the opening |
| Light at the edges | Small gaps at the sides by design | Reduced by the overlap you added |
| Obstructions | Cranks, handles and deep trim can rule it out | Molding and handles still need checking |
Only one of these two measurements gets adjusted for you
The measuring guide published by the seller is unusually direct about this. For an inside mount it instructs: “Do not make deductions”, and says the company will adjust the figure for proper clearance. For an outside mount it instructs the opposite: “Add at least 2 to 3 inches on each side (4 to 6 inches total) to minimize light gaps and ensure full coverage.”
So the two mounts hand the arithmetic to different people. On an outside mount the overlap is a number you choose and can see. On an inside mount the clearance is a number the factory applies to your exact figure, and the guide does not publish what it is. That is not a criticism; a custom manufacturer needs a known tolerance to cut to. It does mean the finished width will not match the number you typed, and that is worth knowing before the box arrives.
The same guide declines to publish the one measurement that decides whether an inside mount is possible at all. It says only that depth requirements vary by product, and directs you to “refer to product specifications on SelectBlinds.com”. The minimum depth lives on each product page rather than in the instructions that tell you how to measure, which means the measuring step and the eligibility step happen in two different places.
What an inside mount blinds versus outside mount blinds check looks like on the page
Run the inside mount blinds versus outside mount blinds question through the storefront and a second gap appears. The navigation at SelectBlinds, read on 2026-10-29, sorts the catalog by product type: cellular shades, roman shades, roller shades, wooden blinds, curtains, shutters, a “No Drill” group and a sale group. There is no mount-type filter anywhere in it.
That matters because mount feasibility is a product attribute, not a preference. A product with a deep headrail cannot inside mount in a shallow window, and no shopper can sort for that. The site does publish its own mounting shortcut in the same navigation, noting that “Tension mounting or adhesive backing eliminates the need to drill holes in your window frame”, which is a third route that sidesteps the question for some products and not others.
The difference between inside mount blinds and outside mount blinds is which number you send
Put concretely, the difference between inside mount blinds and outside mount blinds is a choice between submitting a measured opening and submitting a designed coverage area. Four practical consequences follow:
- An inside mount needs the opening to be reasonably square. The guide allows for imperfection “as long as there are no major variances”, which is a judgment you make with a tape measure in three places.
- An outside mount is the recommended route for shallow windows, and the guide says it also suits anyone who wants “to make windows appear larger and taller”.
- An outside mount has to clear what is already on the wall. The instruction is to “Check for obstructions like molding or handles.”
- Either way the product is built to your figures. The terms state that “As all of our blinds and shades are custom-made”, and that the company “cannot offer a cash refund or exchange unless a product is defective”.
There is also a clock on the decision that is easy to miss. The same terms say that “Changes to orders cannot be made after the expiration of the 4-hour review period”, and that selecting the bypass option at checkout means “no changes can be made to your order”. The mount choice is locked faster than a second look at the tape measure usually happens.
Choosing inside mount blinds or outside mount blinds for beginners
For a first order, inside mount blinds or outside mount blinds for beginners is best decided by the window rather than by the look. Measure the depth of the opening first. If the product page’s minimum depth is deeper than what you have, the decision is already made and no amount of preference changes it.
Where both are possible, the trade is light control against trim. Inside mounts leave the window casing visible and accept narrow side gaps. Outside mounts cover the casing and the gaps along with it, at the cost of a blind that reads as larger than the window.
What to measure before you order
- Measure the opening width at the top, middle and bottom, and the height at the left, midpoint and right.
- Measure the depth from the glass to the front edge of the opening, then compare it to the product page minimum.
- If you are going outside, add the overlap the guide specifies to each side before you write anything down.
- Photograph any handle, crank or deep trim and check it against the headrail depth.
- Submit the exact opening for an inside mount, with no deduction of your own.
The catalog and the measuring help both sit here:
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The one published grade in this aisle is attached to the cords
It is tempting to assume that mounting a blind higher or further out makes a corded product safer around children. The industry’s own certification says otherwise, because it grades the product and not the installation.
The Window Covering Manufacturers Association runs a program under which, once products pass testing, “they may be labeled Best for Kids”. Manufacturers “submit their window covering products to a designated third party testing laboratory”, and named laboratories “will determine if the products meet the criteria of the program”. The qualifying criteria are narrow: products “that have no cords or inner cords that are not accessible”, plus products whose accessible inner cords cannot form a hazardous loop. Other safety hardware does not qualify a product, and the program states that “There are no exceptions to these criteria.”
The buying consequence is clean. The only published, third-party-tested grade in this category attaches to whether a product has reachable cords, and it is indifferent to how high or how wide you hang it. If a household needs that assurance, it is chosen at the product step, not at the mount step.
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Related guides
- Roller Shades vs Cellular Shades: Specs Compared
- Smart Blinds vs Curtains: Specs and Trade-Offs
- Vacuum for Pet Hair vs Regular Vacuum: Bissell
Frequently Asked Questions
These four come up on almost every custom window covering order, and the answers below hold regardless of fabric or operating style.
Ques: How do I know if my window is deep enough?
Measure from the glass to the front edge of the opening at the top, where the headrail will sit, then compare that figure to the minimum depth printed on the specific product page. The general measuring instructions deliberately do not carry a single number, because it varies by product.
Ques: Should I deduct anything from an inside mount measurement?
No. The instruction is explicit that you submit the exact opening and the manufacturer applies the clearance. Deducting yourself produces a blind that is too narrow twice over.
Ques: Does an outside mount really block more light?
It can, because the overlap you add covers the gaps an inside mount leaves at the sides. How much it blocks still depends on the fabric and on how the product closes.
Ques: Can I change the mount after ordering?
Only inside the short review window the terms describe. After that the order is in production as a made-to-measure item, and a non-defective custom product is not returnable for a cash refund.
Bottom line
Pick the mount with a tape measure rather than with a preference. Check the depth of the opening against the product page first, and if both mounts are genuinely possible, choose the inside mount for a tidier window line and the outside mount when covering the edges matters more.
