Guide
How to frame a photograph: mounts, borders, and proportion
A standard off-the-shelf frame is built for a standard rectangle. A photograph rarely is one — it has its own proportions, and the mount, borders and frame should be built around them, not the other way round. This guide covers how that actually works: mount width, optical centering, borderless framing, frame material, and what to do with a panoramic, square, or otherwise unusual shape.
Mount, printed border, or borderless?
Every framed photograph makes one decision before any other: what happens in the space between the image and the frame itself.
Physical mount
A separate mat board sits inside the frame, in front of the print, with a window cut to reveal the photograph. This is the traditional gallery approach — it lifts the glazing away from the print surface and adds visible depth.
Printed border
The border is printed as white space on the paper itself rather than a physical board. It reads visually the same as a mount from a short distance, at a lower cost, and is the better choice for a thinner overall frame.
Borderless
The photograph is printed edge to edge with no margin at all. Pan and zoom to choose exactly what fills the frame. Suits bold or graphic images where any border would compete with the subject.
How wide should the mount be?
Mount width is usually described as a ratio — how much larger the mount or border area is than the photograph it surrounds, rather than a fixed number of centimetres. That ratio is what should change with the image, not an arbitrary preference for “wide mounts” or “narrow mounts.”
Optimal
The mount or border area is roughly twice the area of the photograph — generous breathing room, the most traditional gallery proportion.
Slim
The mount or border area is about one and a half times the photograph's area — a narrower surround for images that can carry less space around them.
Custom
A slider sets the ratio anywhere between slim and considerably wider than optimal, for a photograph that calls for an unusual amount of breathing room in either direction.
Optical centering — solved for every size, not a fixed rule
How Project4 handles it:our framing algorithm calculates the exact bottom-weighting for your photograph and chosen size automatically — there’s no single ratio applied to every order, because what reads as balanced changes with scale, aspect ratio and mount width.
This correction is one of the oldest conventions in picture framing, and it exists for a genuine reason rather than tradition for its own sake. A photograph mounted with mathematically identical borders on all four sides looks, to the eye, as though it has slipped slightly down and to the left of centre. The effect is subtle but consistent enough that framers have corrected for it for well over a century.
Most framing guides hand you a single percentage and leave it there — but the weighting that looks right on a small desk print isn’t the one that looks right on an oversized feature piece, and it shifts again with a panoramic or square crop. Rather than stretching one fixed number across every order, Project4’s solver takes your photograph’s actual proportions, the mount or border width you’ve chosen, and the overall size, and computes the bottom-weighted balance fresh each time — so the result reads as centred at whatever size you order.
Frame width and material
The frame’s own width matters more than its colour. A matt black finish is neutral enough to suit almost any photograph, so the real decision is how wide and how deep the profile itself should be.
| Profile | Material | Width | Depth | Suits |
|---|---|---|---|---|
| Thin | Aluminium | 7mm | 21mm | The slimmest profile — lets the photograph take centre stage. |
| Medium | Aluminium | 11mm | 25mm | A clean, contemporary mid-width, suited to almost any photograph. |
| Classic | Wood | 20mm | 13mm | The widest and shallowest profile, giving the work a heavier border. |
Panoramic, square, and unusual aspect ratios
Standard frame sizes assume a standard rectangle. A panoramic photograph, a square crop, or a portrait with an unusual ratio all fall outside that — which is normally where off-the-shelf framing forces a compromise: crop the image to fit the frame, or accept a mount so lopsided it looks wrong.
Neither compromise is necessary when the frame is built to order. The mount, borders and outer frame dimensions can be calculated directly from the photograph’s actual proportions — however wide, narrow, or square — rather than from a fixed list of ratios. A panoramic landscape and a square portrait both get the same optically centred treatment, sized to fit what the photograph actually is.
It is also possible to decouple the frame’s outer dimensions from the photograph’s aspect ratio entirely — setting a specific width and height independently when a wall or a gap on a gallery wall calls for a particular overall size, with the image centred and cropped to fill it.
Glazing
Every Project4 frame is glazed with 99.7% UV-protective acrylic rather than glass — lighter, shatter-resistant, and significantly reducing the UV exposure that causes prints to fade over time, which matters most for a fine art print intended to last decades.
See your framing choices before you order
Mount width, ratio, and frame profile all update live as you adjust them against your own photograph — including its actual aspect ratio — so you can see the optically centred result before committing.
Once you’re happy with the framing, the same preview carries over to the wall visualiser — so you can check the finished size and proportions on your actual wall in AR before you order.
Upload your photograph and frame it to order
Choose a mount, a frame width, and a size — optically centred and built around your photograph’s actual proportions, whatever they are. No account needed to preview.
Frame your photo — from £53 →Frequently asked questions
How wide should a picture mount be?
Wide enough to give the image breathing room without dwarfing it — in practice, a mount whose exposed area is roughly 1.5 to 2 times the area of the photo itself. A narrower ratio (around 1.5) suits a bold or busy image; a more generous one (around 2) suits a quieter image that benefits from more surrounding space.
Should a photograph border be wider at the bottom?
Yes. Mathematically equal borders on all four sides look bottom-light to the eye — a well-known optical effect in picture framing. Rather than applying one fixed percentage to every order, Project4's framing algorithm calculates the exact bottom-weighting for your photograph's proportions and the size you've chosen, so the balance holds whether it's a small desk print or an oversized feature piece.
What is optical centering in picture framing?
Optical centering is positioning a photograph slightly above true mathematical centre within its mount or frame, with a wider border at the bottom than the top and sides. It compensates for an optical illusion in which equal borders make the image look like it is sinking toward the bottom edge.
Can I frame a panoramic photograph?
Yes. A panoramic image does not need to be cropped to a standard ratio — a frame built to order can be sized to the photograph's actual proportions, however wide or narrow, with the mount and borders calculated around that exact shape.
Do I need a mount, or can a photograph be borderless?
Neither is wrong — it is a style choice. A mount (or a printed border) gives the eye a resting point before it meets the frame, and suits most fine art and documentary photography. Borderless framing, where the image runs edge to edge, suits bold, graphic, or abstract images where the photograph itself should fill the frame with no interruption.
What colour frame should I use for a photograph?
A matt black frame is the most versatile choice for photography — it reads as neutral against almost any image, colour palette, or wall, and doesn't compete with the print. The decision that actually changes the result is the frame's width and material, not its colour.