1. Vector or raster: understand the difference
A vector file (AI, EPS, SVG, vector PDF) describes mathematical shapes: it can be scaled indefinitely without losing sharpness. It's the ideal format for a logo, text or flat-colour illustration.
A raster image (PNG, JPG, TIFF, PSD) is made of pixels. Enlarged beyond its intended size, it becomes blurry or jagged. It's suitable for photos and detailed illustrations, provided it has sufficient resolution.
2. The right resolution, at actual size
The rule: 300 dpi at the print size. A design 30 cm wide should therefore measure about 3 500 pixels wide. An image taken from a website (often 72 dpi and only a few hundred pixels) is not enough for a sweatshirt back.
Note: increasing the resolution of a small image in software does not add detail. You need the original source file or the design must be redrawn.
3. The print size
Prepare the file at the actual size it will be printed. Common reference sizes:
| Placement | Indicative width | Pixels at 300 dpi |
|---|---|---|
| Chest (heart side) | 8 to 10 cm | 950 to 1 200 px |
| Centre chest | 20 to 28 cm | 2 350 to 3 300 px |
| Full back | 28 to 30 cm | 3 300 to 3 550 px |
4. Transparent background
In DTF printing, anything that is not transparent is printed. A logo saved as a JPG will therefore have a white rectangle around it. Export as a PNG with a transparent background, and check there is no white halo around the edges.
Also avoid semi-transparent areas (soft drop shadows, blurs): they do not print well on textiles.
5. Colours
- For a logo, give your Pantone references or colour codes: that's the best basis for a faithful result.
- Keep in mind that screens are luminous and fabric absorbs ink: a very saturated colour on screen may appear slightly softer on the fabric.
- On dark textiles, a white underbase is added to keep colours vivid.
6. Fonts and fine strokes
- Convert texts to outlines (« convertir en contours ») or send the fonts with the file.
- Avoid texts smaller than 2 mm high for printing, and smaller than 5 mm for embroidery.
- Strokes thinner than 0,5 mm may disappear.
7. Flatten and clean the file
Remove hidden layers, elements outside the artboard and crop marks. Keep a non‑flattened working version for future edits, and send a clean final version.
The checklist before sending
- Vector, or PNG at 300 dpi at actual size.
- Transparent background, no halo.
- Texts converted to vector and large enough.
- Colour references indicated.
- Desired placement and size specified in the request.
No usable file? Don’t panic: read I don’t have a file of my logo, what to do? and our guide prepare your logo for printing or embroidery.
