A passepartout is a card border with a window cut in it, sitting between your print and the frame. Do you need one? For a print bought here, usually not. Our frames are built for the exact size of the print, so there is no gap to hide and nothing to trim. A mount is a look you can choose. It is not a repair you have to make.
What is a passepartout, exactly?
Passepartout is the French word, and the one used across most of Europe. In British English it is a mount. Same object: a sheet of thick card, larger than the print, with a rectangular window cut through the middle. The print sits behind the card, the card sits behind the glazing, and what you see is the image surrounded by a clean margin.
The window is cut slightly smaller than the print, so the paper is held at its edges rather than floating loose. That is the entire mechanism. There is nothing clever about it, which is part of why it has lasted.
What does a mount actually do?
Two things, and only two.
First, it gives the image visual breathing room. A busy print pressed straight up against the moulding can feel cramped; a border of plain card gives the eye somewhere to rest before it reaches the wall. On a dense composition that is a real improvement. On a minimal one it is often redundant, because the print already has its own white space built in.
Second, it holds the print off the glass. Paper touching glass can stick over time, and it happens fastest where humidity swings — a bathroom, a kitchen, an unheated hallway in winter. The card works as a spacer: a few millimetres of air between the two surfaces.
Everything else claimed for a mount is taste rather than function. Sometimes correct. Not a reason on its own.
Framed edge to edge, no mount required
Green HilmaTara Green
Rothko Orange Perspective
Bauhaus Woman 03David Wolf
Tree of Life CollageThomas Nordentoft
Hilma No 02Tara Green
Bauhaus Woman 02David Wolf
Not sure a mount is worth the frame size? Every one of these is printed to fit its frame exactly, in all five sizes. Shop all best sellers →
Do you need one for a print bought here?
Usually not, and the reason is unglamorous: our frames are made for the exact print size — A4, A3, 50×70, 70×100 and 100×140 cm. A 50×70 print goes into a 50×70 frame with nothing to trim and no gap to disguise.
That matters because a mount is most often used to solve a problem you do not have. If a print is an odd size, or was cut down, or came from somewhere that framed to different standards, a mount covers the mismatch and makes the result look deliberate. Buy the print and the frame in the same size and the problem never appears.
The second reason to think twice is arithmetic. If you want a mount, you size up. To show a 50×70 print with a border around it you need a larger frame — or you accept that the visible image is smaller than the frame. A mount always costs you either frame size or image size. There is no third option, and no amount of careful cutting invents one.
Worth settling your sizes before you decide anything else: our poster size guide covers all five in centimetres, including why A2 is 42 × 59.4 cm and does not fit a 50×70 frame.
How wide should the border be?
Wider than most people first guess. Typical mount borders run 4–8 cm on small prints and 6–10 cm on large ones. Narrower than that reads as timid, as though the card ran out. Wider reads as gallery.
| Print size | Typical border width | Added across width and height |
|---|---|---|
| 21 × 30 cm (A4) | 4–6 cm | 8–12 cm |
| 30 × 42 cm (A3) | 5–8 cm | 10–16 cm |
| 50 × 70 cm | 6–8 cm | 12–16 cm |
| 70 × 100 cm | 8–10 cm | 16–20 cm |
| 100 × 140 cm | 8–10 cm | 16–20 cm |
These are ranges, not prescriptions — there is no correct number, only a band that tends to look right. Read the third column carefully, because that is the cost. A 70×100 print with a 9 cm border needs an opening 18 cm larger in both directions than the print itself, and the three largest sizes we sell are exact round centimetre sizes rather than A-formats, so the frame that would take it is not simply the next size up the alphabet.
Why is the bottom margin deeper?
The traditional cutting convention is equal margins at the top and the two sides, with the bottom margin roughly 10–20% deeper. Written down it looks like a mistake. On a wall it looks right.
The reason is that the eye reads a mathematically centred image as sitting slightly low. The deeper bottom margin corrects the illusion. Framers call it optical centring, and on a 50×70 print with a 7 cm border it means about 7 cm at the top and sides and 8 cm along the bottom — small enough that nobody consciously notices. That is the point of it.
When is a mount the right call?
Three cases, honestly.
The print did not come from us and does not match any frame you can buy off a shelf. A mount is the proper fix, not a bodge.
The image runs strong colour right to its edge and you want a pause between the picture and the moulding. Entirely a matter of taste, and a legitimate one.
The wall is somewhere humidity moves — a bathroom, a kitchen, a summer house shut up over winter. Here the spacer function earns its place on its own, whatever the image looks like.
Outside those three, a print made for its frame is finished as it is. We do not sell mounts, and this is one of the few articles where that turns out to be the useful answer rather than an awkward one.
What to do instead
Order the print and the frame in the same size and skip the question entirely. Oak and black are made for every size on that list; if a colour is what you are after, you are choosing among the sizes up to 50×70. And if you would rather not assemble anything, our framing service handles the fitting and the glazing at our end, so what turns up is a finished picture with nothing left to do but hang it.
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