Design at 300 DPI at the final print size, export a transparent PNG in RGB / sRGB, and never upscale a small file to fake the resolution. Hit that and most products pass on the first try.
Why resolution is really about pixels
“300 DPI” on its own is meaningless without a size. DPI (dots per inch) only tells the printer how densely to lay ink; what your file needs is enough pixels to fill the print area at that density. The formula is simple:
pixels needed = print size in inches × DPI
So a 12×16 inch t-shirt print at 300 DPI needs 3600×4800 px. If you're fuzzy on the difference between DPI and PPI, our DPI vs PPI guide clears it up in a couple of minutes.
Platform-by-platform requirements
| Platform | Resolution | File format | Notes |
|---|---|---|---|
| Printful (DTG) | 150 DPI minimum, 300 DPI recommended | PNG (RGB), transparent | Up to 200 MB per file; match the product's print-area template |
| Printify | 300 DPI recommended | PNG or JPG | Requirements vary by print provider — check each mockup for coverage |
| Redbubble | 300 DPI, one large master file | PNG, sRGB | ~7632×6480 px master scales to every product; 2400×3200 is the practical floor |
A note on Redbubble: because a single upload is stretched across dozens of products (from stickers to duvet covers), you want the biggest file you reasonably can. Redbubble publishes an ideal of 7632×6480 px for full-bleed products. You rarely need that for a simple logo tee, but for edge-to-edge artwork it's the difference between crisp and blurry on the large items.
Pixel dimensions per print area at 300 DPI
Rather than memorize each platform's templates, keep this cheat sheet. Multiply the physical print area by 300 and you have your minimum canvas.
| Print area | Pixels at 300 DPI | Typical use |
|---|---|---|
| 4×4 in | 1200×1200 px | Left-chest logo, small sticker |
| 8×10 in | 2400×3000 px | Mug wrap, small poster |
| 11×14 in | 3300×4200 px | Standard front print, art print |
| 12×16 in | 3600×4800 px | Full t-shirt / hoodie front (DTG) |
| 24×36 in | 7200×10800 px | Large wall poster |
Large-format items (posters, canvases, all-over prints) are viewed from a distance, which is why Printful and others accept 150 DPI for them — it halves the pixel requirement without visible loss. Apparel viewed up close should stay at 300 DPI where you can.
Color mode and transparency
Almost all direct-to-garment (DTG) and Redbubble printing works in RGB, with an sRGB profile — do not convert to CMYK for these, or your colors will shift and dull. CMYK only comes up with certain commercial offset providers, and even then the platform usually converts for you.
Export a transparent PNG so the garment or product color shows through around your design. A common failure is a “transparent” PNG that actually has a white box baked in — it prints as a white rectangle on a black shirt. Always preview on a dark mockup to catch it. You can match an exact garment color across HEX, RGB, HSL & CMYK with the Color Code Converter.
Vector vs raster: start at the source
Whenever your design is type, logos or flat illustration, build it as vector (in Illustrator, Affinity Designer or free Inkscape) and export the raster PNG at your final pixel size. Vector art is resolution-independent — the same source exports crisply at 1200 px for a sticker or 4800 px for a hoodie, with no quality loss. Photographic or painted art can't be vector, so for those you must capture or create at the largest size you'll ever need up front, because you can scale down cleanly but never up.
Read the print-area template, not just the mockup
The glossy product mockup shows how the design looks; the print-area template shows where it can actually go. Each provider defines a maximum printable rectangle (for example, a common DTG front is 12×16 in). Anything outside that rectangle is silently cropped by the printer — a frequent surprise when a design that looked centered in the editor arrives shifted or clipped. Download the provider's template and design within its bounds, keeping key elements away from the very edges.
Mistakes that get designs rejected or refunded
- Upscaling a low-res file. Enlarging 800×800 to 3600×3600 doesn't add detail — it prints soft and pixelated. Start large or redraw as vector.
- Heavy JPEG artifacts. Re-saving JPGs introduces blocky halos around edges that DTG faithfully reproduces. Keep your master as PNG.
- Hairline details under ~2 px. Thin lines and tiny text can drop out entirely on fabric. Keep strokes chunky.
- Wrong color mode. CMYK files on an RGB DTG pipeline come out muddy.
- Ignoring the safe / print area. Art outside the template bounds gets cropped by the printer, not centered how you expect.
A reliable prep routine
- Decide the largest physical size your art will print at.
- Multiply by 300 (or 150 for large format) to get your canvas in pixels.
- Build at that size from vector or high-res sources — never upscale.
- Export transparent PNG, sRGB, and preview on both light and dark mockups.
- Run the file through the Etsy & Amazon Resizer to confirm the effective DPI at your target size before uploading.
Do this once per design and rejections basically stop. When in doubt, err bigger — you can always scale a large file down, but you can never add detail that was never captured.