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Why does my 300 DPI image still print blurry?

By Osmanth Image · Updated October 13, 2026

The 300 DPI stored in a file is only a label. What decides sharpness is the number of pixels divided by the inches you print across. A 2,400 × 3,000 px image is 300 pixels per inch at 8×10 in but only 150 at 16×20 in, whatever its label says. Check the pixel count against the print size.

The short version

The same pixels at four print sizes

One image, 2,400 × 3,000 pixels, printed at four sizes. Only the size changes, so only the pixels per inch change. The last column is the target and the lowest figure the check uses for that size; they are Osmanth Image's own guideline for judging a print, not a printer's rule.

Print sizePixels per inchTarget and lowest PPI the check usesWhat the check says
8×10 in300300 and 180Plenty of detail for this size.
12×15 in200300 and 150Enough detail at normal viewing distance, but it won't be tack-sharp up close.
16×20 in150300 and 150Enough detail at normal viewing distance, but it won't be tack-sharp up close.
20×25 in120200 and 100Enough detail at normal viewing distance, but it won't be tack-sharp up close.

The figure that matters is the second column, and it moves with the print size. The label inside the file never appears in that calculation.

What we tested

We built two test JPEG files with the same pixel size, 2,400 × 3,000. One carries a 72 DPI tag and the other a 300 DPI tag. They contain only the file structure the check reads, no picture. We ran both through the check for an 8×10 in print.

Both came out at 300 pixels per inch with the same verdict: "Plenty of detail for this size." The check shows the tag in its details ("Embedded DPI setting: 72 (jfif) — does not affect quality") and, for the 72 DPI file, notes that it will correct the print-size setting in the file it prepares. That correction changes a number stored in the file. It does not change the verdict, because the verdict comes from the pixels.

What does make a print look soft

  1. Too few pixels for the size. Printful's help center gives its own example: a 5″ × 5″ image at 100 DPI scaled up to 10″ × 10″ without changing the resolution drops to 50 DPI, "meaning the print will look blurry." Printful asks for files that are at least 150 DPI and sized to match the actual print dimensions.
  2. A soft or heavily compressed original. More pixels cannot add detail the picture never had. The check estimates how heavily a JPEG was compressed and tells you if it is likely to show blocky patches in print. It does not measure how blurry a picture is, so a soft original can pass the pixel check and still print soft.
  3. A print size the product was never meant for. Targets differ by product. Printify's help center says 300 DPI is recommended for JPEG and PNG files, that a lower resolution might also be sufficient depending on the product, and that large products such as leggings, blankets or tapestries require 120–150 DPI.

How to check yours

  1. Find the pixel size of the image. Once you choose the file in the check, its width and height in pixels appear in Step 1.
  2. Decide the print size in inches.
  3. Divide the pixels across by the inches across. If 2,400 pixels span 8 inches, that is 300 pixels per inch.
  4. Compare the result with the target for that print size. If it is lower, print smaller, or find a larger original. The check shows how large the image prints well.

Editing the DPI box in an image program does not change any of this. If the program resamples the image, it adds or removes pixels, which changes the file but adds no detail. For the pixel counts of common poster sizes, see poster size in pixels.

Limits and what we are unsure of

The check runs on your device and your image is not uploaded; the privacy page explains exactly what that means.

Sources

Printers and marketplaces change their rules. Each page below was read on the date shown; check it again before you rely on it.