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. If you want 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 just 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 PNG, every time
Save as a PNG with a transparent background. Transparency tells the printer exactly where ink and the white underbase should and should not go — anything that is not part of your artwork must be fully transparent, not white. A white background will print as a white rectangle around your design. JPG cannot hold transparency and adds compression artifacts, so it is the wrong format for a transfer.
Vector source files (AI, PDF, SVG) are excellent because they scale without quality loss, but export a flattened transparent PNG at final size for the actual transfer.
What the green / amber / red check means
When you place art in the builder or upload a ready-to-press file, each object gets a live DPI badge at its placed size. Green means 300 DPI or higher — press with confidence. Amber means 150 to 299 DPI — usable for many designs but softening detail, so shrink the object or swap in a higher-res file if it matters. Red means below 150 DPI — expected to look pixelated or fuzzy when pressed.
Red results are gated: you either fix the file or explicitly acknowledge the low resolution before adding to cart, and below a hard floor of 100 DPI add-to-cart is blocked outright, with no override, because it will not press acceptably.
Color, black, and fine detail
Design in RGB — our print pipeline handles the conversion, and pushing colors through your own CMYK profile first usually dulls them. For deep blacks, use a true 100% black rather than a muddy near-black. Very thin lines and tiny text are the first things to break down: keep strokes and small type reasonably thick so they survive printing and the wash.
Because DTF lays down a white underbase, your colors stay bright even on a black shirt, but semi-transparent and feathered edges can pick up a faint white halo, so favor clean, solid edges where you can.
The mistakes that cause reprints
The usual culprits: pulling a logo off a website (those images are around 72 DPI and far too low), scaling a small graphic way up, leaving a white background instead of transparency, or sending a screenshot. Before you submit, view the file at 100% zoom at its real size — if it looks soft there, it will press soft.
Every order also gets a free art check, so if something is borderline we flag it before it prints, but the fastest path to a perfect transfer is a clean 300-DPI transparent PNG built at the size you actually want.