Full guide
Print-on-demand image requirements
Most of what is published about print-on-demand file specs is second-hand and out of date — Merch dropped its exact-size rule and half the internet still teaches it. Every number below was read off the platform's own documentation, and every row says when.
The four platforms, side by side
Scroll sideways on a narrow screen. Dimensions are set per product on three of the four — any guide quoting one pixel size for a whole platform is quoting a single product page.
| Platform | Formats accepted | Max file | Max pixels | Dimensions | Density |
|---|---|---|---|---|---|
| Printful | PNG, JPEG PDF accepted, not advised | 200 MB | 20,000 × 20,000 | Per product and print area | ≥150 DPI no rejection line |
| Printify | JPEG, PNG, SVG | 100 MB SVG 20 MB | — | Per product and print provider | 300 DPI advised 120–150 for large format |
| Redbubble | JPEG, PNG only no SVG, no PDF | 300 MB | 13,500 × 13,500 | Per product minimum Graphic Tee 3873 × 4814 | No platform threshold |
| Merch by Amazon | PNG only | 25 MB | — | Above 485 × 485 aim for 4500 or more | 300 DPI advised no rejection line |
Where each number comes from
- Printful — How should I prepare my print file for the best results?
Verified 6 October 2026 · document dated 6 October 2026 - Printify — What type of print files does Printify require?
Verified 6 October 2026 · document dated 29 September 2026 - Redbubble — Dimensions & Format
Verified 6 October 2026 · document dated 4 August 2026 - Merch by Amazon — Best Practices — Artwork tips (sign-in required)
Verified 14 September 2026 - Etsy — Requirements and Best Practices for Images in Your Etsy Shop
Verified 6 October 2026 · document dated 6 October 2026
Batch, auto-fix and exports
Everything above is free for one file at a time, and always will be. Doing it to a whole folder — batch checking up to 100 files, one zip with every platform file for every design, and a CSV report — is part of Seller.
Exports are padded and centred to each platform's size on a transparent canvas. Nothing is ever upscaled — a file enlarged to pass a dimension check still prints soft, which is the failure this tool exists to prevent.
When these numbers last changed
Specifications get revised without announcement — Merch by Amazon removed its exact-size requirement and the old wording simply became "previously required". Every change we confirm is recorded with its date and the platform's own sentence in the [spec change log](/spec-changes), and the same dates are published machine-readable at [/specs.json](/specs.json).
Three rules that catch people who did everything else right
No platform accepts WebP. Several design tools now export it by default, and a WebP file fails at upload on all four with no useful message. PNG is the only format all four take, and the only one of those that keeps a transparent background. Merch no longer requires exactly 4500 × 5400. Its current editor accepts anything above 485 × 485 and scales it to fit, and it asks you to trim the transparent margin rather than pad to a canvas. A checker still testing for the old exact match will fail files Amazon would have accepted. Printful refuses a file name with two dots before the extension. `design..png` fails to upload, and export scripts produce that shape more often than you would think.
One file that satisfies all four
Build at 4500 × 5400 pixels, transparent PNG, sRGB, under 25 MB. That clears every one of the four: it is 15 × 18 inches at 300 DPI, it is comfortably above Merch's 485 floor and its 25 MB ceiling is the tightest of the four, it scales down to every Redbubble product size, and it leaves a Printful size run 100% of headroom before the density floor. Nothing here requires you to build four files — it requires you to build to the strictest one.
By platform
The other half: the image buyers see
Everything above is about the file that gets printed. The photo on your product page is a different image governed by different — sometimes opposite — rules. Etsy, where a great many print-on-demand sellers actually list, does not support transparency at all: upload the transparent PNG you prepared for the printer and the transparent areas [render as solid black](/etsy-listing-image-requirements). It is worth checking both.
Listing images
Already rejected?
Frequently asked questions
Can one file work across all four platforms?
Yes. 4500 × 5400, transparent PNG, sRGB, under 25 MB clears all four. The 25 MB ceiling is the binding constraint, and it is the one a gradient or a grain overlay will push you past.
How current are these numbers?
Each row above links to the platform documentation it came from and carries the date it was last read, along with the date that document itself was last updated. Specs change quietly — Merch dropped its exact-size requirement without announcement — so check the source before an upload that matters.
Which platform catches sellers out most often?
Redbubble. It rejects almost nothing, so problems only surface when a customer receives the product — and its highest-margin categories are the large formats most sensitive to resolution.
Why does this page not quote one pixel size per platform?
Because three of the four do not have one. Printful sets requirements per product and print area, Printify per product and print provider, Redbubble per product. Only Merch has a platform-wide dimension rule, and it is now a floor of 485 × 485 rather than an exact size.