The short answer: 300 DPI at the actual print size. A logo intended for a 8 cm chest must be at least 945 pixels wide; a back design of 29,7 cm, at least 3 508 pixels. Below 150 DPI, the outlines become visibly jagged once pressed.
Why actual size matters more than the number of pixels
A file 1 000 pixels wide is excellent for a 8 cm chest logo (317 DPI) and insufficient for a 30 cm back (85 DPI). DPI is not a property of the file, it is the ratio between its pixels and the size at which it is printed. That is why our designer calculates the effective resolution once the artwork is placed and resized on the garment, and warns you if it falls below the threshold.
Guidelines by placement
| Placement | Usual size | Minimum file width |
|---|---|---|
| Chest | 8 × 8 cm | 945 px |
| Chest | 12 × 12 cm | 1 420 px |
| A4 front | 21 × 29,7 cm | 2 480 px |
| A3 back | 29,7 × 42 cm | 3 508 px |
| 58 × 100 cm sheet | 58 × 100 cm | 6 850 px |
PNG, JPG or PDF?
For DTF, the PNG with a transparent background is the ideal format: the transparency defines exactly what will be printed, and the printed white sits under the design. A JPG has no transparency: the whole rectangle is printed, background included. A vector PDF (logo exported from Illustrator or Inkscape) is perfect for a print-ready sheet: it has no resolution, it stays sharp at all sizes.
How to check it yourself
Open your file and note its width in pixels. Divide by the print width in inches (centimetres ÷ 2,54). The result is your actual DPI. Example: 2 000 px for a 25 cm front → 2 000 ÷ 9,84 = 203 DPI. Acceptable for photographic artwork, a bit tight for a logo with sharp outlines: ask your graphic designer for the source file or reduce the print size.
What if I only have the logo in a small size?
Three ways out. Reduce the print size until you get back to 250 to 300 DPI. Redraw the logo as a vector, which is often quick for a simple logo, and we can do it for a quote. Or accept a slight blur on photographic artwork, where it is less visible than on text. The designer shows you the result before you order: you decide with full knowledge.