Your product image aspect ratio decides which part of your spec diagram a buyer never sees. Export a 16:9 dimension drawing, upload it to a storefront that renders square thumbnails, and the platform removes roughly 22% of the width from each side — which is exactly where the leader lines and the millimetre callouts live. The photo still looks fine. The measurements are gone.
What follows is a gallery of the crops that eat dimension labels: what each one looks like, why it happens, and the export setting that stops it. Every platform number below comes from that platform's own published documentation; every percentage comes from the arithmetic of the crop itself.
What product image aspect ratio actually controls
Product image aspect ratio is the ratio of an image's width to its height — 1:1 square, 4:5 portrait, 3:2 or 16:9 landscape — and it decides what a storefront keeps when it fits your file into a fixed-shape slot. Storefronts almost never letterbox a product image with white bars; they centre-crop it to fill the slot.
That single behaviour is the whole problem. A centre crop never removes the middle of your photo. It removes the edges — and the edges are where you put the numbers.
Here is what a centre crop costs, as pure arithmetic:
| You export | Slot renders | Kept | Lost in total | Lost per side |
|---|---|---|---|---|
| 16:9 landscape | 1:1 square | 56.3% of width | 43.7% | 21.9% |
| 3:2 landscape | 1:1 square | 66.7% of width | 33.3% | 16.7% |
| 4:3 landscape | 1:1 square | 75% of width | 25% | 12.5% |
| 1:1 square | 4:5 portrait | 80% of width | 20% | 10% |
| 1:1 square | 2:3 portrait | 66.7% of width | 33.3% | 16.7% |
| 4:5 portrait | 1:1 square | 80% of height | 20% | 10% (top and bottom) |
Read the last three rows twice if you push the same asset to a marketplace grid and a social catalogue. The identical file gets cut on the sides in one place and on the top and bottom in the other. There is no single export that survives both by luck — only one that survives both by design.
Anti-pattern 1: the widescreen spec diagram
What it looks like: a beautiful 1920 × 1080 drawing of a sofa with overall width on the left, seat depth on the right, and a scale bar underneath. In the search grid it appears as a square with the sofa filling the frame and no numbers at all.
Why it happens: 16:9 is the default canvas of nearly every screen-recording and presentation tool, so it becomes the default canvas for diagrams too. It is also the worst possible source ratio for a square slot — it loses 43.7% of its width.
The fix: build dimension diagrams on a square or 4:5 canvas from the start. If the product is genuinely wide, shrink the product rather than widening the canvas. You lose a little apparent size and keep 100% of the annotation.
Anti-pattern 2: labels parked in the outer margin
What it looks like: the numbers sit tight against the frame edge, aligned like a technical drawing. One re-crop and the "1" of "1200 mm" is missing, leaving "200 mm".
Why it happens: drafting habits. In CAD, dimensions belong outside the object outline. On a marketplace, outside the object outline means inside the crop zone.
The fix: treat the central 80% of the canvas as the only safe area. That 10% margin on every side is not a superstition — it is the exact amount consumed by the two most common conversions in e-commerce, 1:1 to 4:5 and 4:5 to 1:1, both of which remove 10% per affected side. Anything you cannot afford to lose lives inside that box.
Google's image link requirements push in the same direction from a different angle: Google asks you to frame the product so that it occupies "no less than 75%, but not more than 90%, of the full image." A product filling 90% of the frame leaves you 10% of breathing room in total — so labels stacked outside the product are already living on the crop line.
Anti-pattern 3: leader lines that run off the edge
What it looks like: an arrow starts at the cabinet's left edge and points off-canvas to a number that no longer exists. Buyers read it as a rendering bug, not as a missing label.
Why it happens: the annotation was drawn against the original photo's bounds, not against the safe area.
The fix: anchor every leader line so that both ends — the measured edge and the text — fall inside the safe area. A dimension line that terminates in a visible arrowhead and a visible number survives cropping as a self-contained unit. Placement details for that are covered in product photo callouts.
Anti-pattern 4: the border
What it looks like: a thin grey or black frame around the diagram, added to make it feel like a document.
Why it happens: it looks tidy in a PDF catalogue, and people reuse the catalogue asset on the storefront.
The fix: delete it. Google states plainly: "Don't use an image with a border." Beyond the policy, a border is the first thing a crop slices, so what a shopper sees is a broken half-frame on two sides — the visual signature of a low-effort listing.
Anti-pattern 5: promotional text sitting next to the measurements
What it looks like: "Free shipping" and a price flash in the corner, right beside a legitimate dimension callout.
Why it happens: one designer, one canvas, two jobs.
The fix: separate them, and know the line. Google's image requirements disallow calls to action, price information, promotional adjectives, watermarks, and brand or retailer names in the image unless they are inherent to the product. Descriptive dimension text is not promotional text — a "1200 mm" label describes the item the way a printed size on a garment tag does. Mixing the two on one canvas is what gets a genuinely useful spec image caught in a promotional-overlay filter.
This is the most commonly over-corrected rule in the category. Sellers hear "no text on images" and strip their dimension labels, then wonder why pre-sale size questions climb. The rule targets marketing copy, not measurements.
Anti-pattern 6: the undersized export
What it looks like: a 900 × 900 px diagram that reads perfectly on your laptop and turns into grey mush in the zoom view.
Why it happens: exports get sized for the layout you are looking at, not for the largest slot the platform will ever render.
The fix: export large and let the platform downscale. Google's image link requirements state images should be at least 500 × 500 px and recommend 1500 × 1500 px or larger, with a ceiling of 64 megapixels and 16 MB per file. Thin annotation strokes and 2 mm-tall digits are the first casualties of upscaling, so the floor that matters for a spec diagram is not the platform's minimum — it is whatever keeps your smallest digit legible after the platform's own compression.
The ratios that are actually documented
Most marketplaces publish their image rules inside the seller console, behind a login, which is why so much of the advice online is second-hand. These are the ones you can read publicly and cite:
| Platform | Publicly documented guidance | What it implies for annotation |
|---|---|---|
| Google Shopping / free listings | At least 500 × 500 px; 1500 × 1500 px or larger recommended; max 64 MP and 16 MB; product fills 75–90% of the frame; no borders; no promotional overlays or watermarks | Square-friendly, tight framing, so keep callouts inside the product's own bounding area where possible |
| 2:3 ratio recommended (1000 × 1500 px); Pins beyond a 2:4.2 width-to-height ratio get truncated in the feed | A square diagram loses 16.7% per side here; build a portrait variant rather than reusing the square | |
| Shopify themes | Product media rendered into responsive, commonly square containers; theme code typically requests images at 2048 px | Uniform ratio across a product's media set is what keeps the gallery from jumping |
For Amazon, Walmart, eBay and Etsy, read the current image requirements inside your own seller console rather than trusting a blog table — those pages change without announcement, and the version you can verify under your account is the one that governs your listing. A cross-platform view of where these rules differ is in listing photo safe zone.
How to stop losing labels for good
The durable fix is not a better crop guess, and it is not memorising every platform's product image aspect ratio. It is to stop treating the diagram as a picture with text on top, and start treating it as measured data bound to the image.
When dimensions are locked to the product's real, measured edges — snap the measurement to the edge, let the label position derive from that anchor — re-exporting at 1:1, 4:5 and 2:3 becomes a re-render rather than a redraw. The numbers stay attached to what they measure, and each export lands at the target ratio with the safe area already respected. That is a different job from what a generic photo editor does with a text box, and a very different job from an AI image generator, which will happily produce a plausible-looking "1200 mm" that was never measured against anything. Plausible is worse than absent: an invented number that a buyer trusts is a return waiting to be filed. Tools built for this are compared in tools to add dimensions to product photos, and the same measured-export logic is what makes a multi-page spec sheet consistent across a catalogue.
Pre-export safe-area checklist
Run this before any diagram leaves your machine:
- Canvas is 1:1 or 4:5 — not 16:9, not an arbitrary photo crop
- Every number and arrowhead sits inside the central 80% of the canvas
- No leader line touches or exits the frame edge
- No border, no drop shadow frame, no decorative rule
- No price, no "sale", no watermark, no logo on the same canvas as the dimensions
- Longest side at least 1500 px, file under 16 MB
- Smallest digit still legible after the file is scaled to a 300 px thumbnail
- A portrait variant exists if you publish to a 2:3 surface
- The same product's images all share one aspect ratio
FAQ
What aspect ratio should product images be?
The safest product image aspect ratio is square (1:1) for marketplace grids and 4:5 for portrait-first surfaces, both exported from the same square-safe layout. Square is the most forgiving source ratio because the two common conversions away from it — to 4:5 and back — each cost only 10% per affected side. Landscape ratios are the expensive ones: 16:9 loses 43.7% of its width the moment it enters a square slot.
Why do my product images get cropped on marketplaces?
Because storefronts fill fixed-shape slots by centre-cropping rather than adding white bars, so any part of the image outside the slot's shape is discarded. It is not a bug or a failed upload — it is the normal fitting behaviour, and it always takes from the edges first.
Can I put dimension text on a product image?
Yes on secondary and infographic images, and it is one of the highest-value things you can put there. What platforms restrict is promotional overlay — prices, calls to action, watermarks, brand badges. Google's image requirements name those categories specifically. A measurement label is descriptive product information, not marketing copy. Check your own seller console for the rules on the main image slot, which is usually the most restricted one.
Does one square image work everywhere?
It works almost everywhere, which is not the same as everywhere. Pinterest recommends 2:3 and truncates Pins past a 2:4.2 ratio, so a square asset there is cropped 16.7% per side or shown smaller than a native portrait Pin. If a surface matters to your traffic, export a native variant for it rather than accepting the crop.
How big is the safe area, exactly?
Keep everything you cannot lose inside the central 80% of the canvas — a 10% margin on all four sides. That margin is derived, not arbitrary: it is exactly what a 1:1 to 4:5 conversion removes per side, and what a 4:5 to 1:1 conversion removes from the top and bottom.