A blurry or pixelated result is almost always caused by a file that does not have enough pixels for the size you are printing. Here is how to find the cause and fix it.
Common causes
The file does not have enough pixels for the print size. A file that looks perfect on screen can still be too small for a large print. What matters is the number of pixels spread across the finished size.
A small image was enlarged. If you take an 800 x 1,000 pixel image and print it large, the missing detail cannot be invented. The print looks soft or blocky.
The file was exported with heavy compression. A JPEG saved at a low quality setting loses detail permanently. Always export at a high quality setting.
The source was a screenshot or a social media download. Both are already reduced in size and quality. Always start from your original artwork.
How much resolution you need
Printumo produces print files at two different resolutions:
Fine art paper prints: 300 DPI at the ordered size.
Canvas prints: 150 DPI at the ordered size. The canvas texture softens fine detail, so canvas needs fewer pixels than paper.
The formula is pixels = (centimetres ÷ 2.54) × DPI. For example:
30 x 40 cm on paper: 3,543 x 4,724 pixels
30 x 40 cm on canvas: 1,772 x 2,362 pixels
50 x 70 cm on paper: 5,906 x 8,268 pixels
50 x 70 cm on canvas: 2,953 x 4,134 pixels
How to fix it
Check the pixel dimensions of your file against the numbers above for the largest size you want to sell.
Go back to the original artwork. Use the full resolution export from your camera, scanner or design software, not a copy you shared or downloaded.
Export with a high quality setting. For JPEG, use quality 90 or above (10 or above in Photoshop). For PNG, make sure it has not been downscaled.
Use the sRGB colour profile so the colours stay consistent.
Upload the file again and check the quality dots on each size.
Check the quality dots
After you upload, every print size in the product editor shows a coloured dot. Dark green and green mean the file is good for that size. Amber means average. Red means the file is too small and the print will look soft.
The dots inform you, they do not block you, so it is worth checking them before you launch a product.
Do not enlarge a small file
Increasing the pixel dimensions of a small file in your design software does not add real detail. It stretches the pixels you already have, and the print looks softer, not sharper. If your original file is too small, choose a smaller print size instead.
Quick checklist
300 DPI at the print size for paper, 150 DPI for canvas
The original artwork file, not a screenshot or a download
Exported at a high quality setting
sRGB colour profile
Green quality dots on every size you offer