Guide
Design a print-ready file
One rule covers most of it: 300 DPI, transparent background, at the exact size you want it pressed. Here is how to hit that, and the mistakes that lead to a soft print.
The one rule: 300 DPI at final size
Resolution only means something relative to how big the image will be printed. A file is "300 DPI" only at a specific physical size, so the rule is 300 dots per inch at the final pressed dimensions. For a 10-inch-wide back print, your file needs to be about 3,000 pixels wide (10 in × 300 DPI).
Scaling a small image up in software does not add real detail; it spreads the same pixels thinner, which is why a logo that looks crisp on screen can press blurry. Start from the largest, highest-quality original you have and size it to the real print dimensions.
Transparent background, every time
Save your artwork with a transparent background. Anything that is not part of the design must be fully transparent, not white: a white background prints as a white rectangle around your design.
JPG cannot hold transparency, so a JPG always prints as a full rectangle. Uploads can be PDF, JPG, PNG, AI, PSD or CDR, up to 25 MB; SVG is not accepted.
Black and fine detail
Deep blacks print best from a solid, true black rather than a muddy near-black. Very thin lines and tiny text are the first things to break down, so keep strokes and small type reasonably thick.
Because DTF lays down a white underbase, colours stay bright even on a black garment, but semi-transparent and feathered edges can pick up a faint white halo, so favour clean, solid edges where you can.
The mistakes that cause a soft print
The usual culprits: a logo pulled off a website (usually far too low resolution), a small graphic scaled way up, a white background instead of transparency, or a screenshot.
Before you upload, view the file at 100% zoom at its real size. If it looks soft there, it will press soft.