Clearing it up
DPI means nothing without a size
This is the most misunderstood idea in print-on-demand, and the root cause behind most rejected files.
DPI is a ratio, not a property
DPI expands to "dots per inch". Because it is per inch, it only means something once attached to a physical size. The identical file is 600 DPI printed across 5 inches and 200 DPI printed across 15 — and not one byte of the file changed.
One 3000px-wide file at different print sizes
| Printed 5″ wide (sticker) | 600 DPI — plenty of headroom |
|---|---|
| Printed 10″ wide (tote) | 300 DPI — exactly on target |
| Printed 15″ wide (t-shirt) | 200 DPI — soft |
| Printed 24″ wide (poster) | 125 DPI — visibly blurry |
So what is the DPI value in the file?
It is metadata: a note telling layout software how large the author intended the image to print. It can be edited freely and editing it does not add a single pixel. Changing 72 to 300 will not change any platform's verdict, because platforms compute pixels divided by print-area size.
Batch, auto-fix and exports
Checking one file at a time is free and always will be. Batch checking up to 100 files, one-click exports sized for every platform, and CSV reports are 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.
Frequently asked questions
Will changing 72 DPI to 300 DPI get it approved?
No. That edits one metadata field and leaves the pixel count identical. Platforms calculate pixels divided by print-area inches.
What size should I design at?
Work to the target platform's recommended pixel dimensions rather than to a DPI number. Get the pixel count right and the DPI takes care of itself.