Printing Planet UK
Getting your artwork right before you submit an order is one of the most important steps in custom printing. The file format you send us directly affects the sharpness, colour accuracy and overall quality of the finished garment. At Printing Planet UK in Putney, we check every file before we print and offer a free artwork setup service, but understanding the basics saves time and helps you get exactly what you want.
Raster vs Vector: The Core Difference
All print files fall into one of two categories.
Raster files are made up of pixels. They work brilliantly for photographs and detailed artwork, but they lose quality when scaled up. If you send a small raster file and ask us to print it large, the result will look blurry or pixellated.
Vector files are made from mathematical paths and lines. They scale to any size without any loss of quality, which is why professional designers always use vectors for logos and text-based artwork.
File Formats Explained
PNG (Recommended for photos and detailed art)
PNG is the most common file type we receive. It supports transparent backgrounds, which is essential for printing on coloured garments. If you send a JPEG with a white background and your shirt is navy blue, you will end up with a white box around your design.
Always supply PNG files at 300 dpi minimum. Anything lower will print soft or pixellated.
PDF (Press-Ready)
A press-ready PDF preserves fonts, colours and layout exactly as you set them up. It is the preferred format for multi-element designs with text because it embeds font data and prevents font substitution errors. If your design was built in Adobe InDesign or Canva Pro, export to PDF for print and you will be good to go.
AI and EPS (Professional Vector)
Adobe Illustrator (.ai) and Encapsulated PostScript (.eps) files are the gold standard for logos, icons and anything text-based. These are fully scalable and give us the cleanest possible output, especially for screen printing where each colour is separated individually. If you have an AI or EPS file, always send it.
JPEG (Avoid Where Possible)
JPEG is a compressed format designed for the web. Every time a JPEG is saved, it loses data, creating visible artefacts at the edges of shapes and text. It also lacks transparency support. Use PNG instead for any artwork that needs a transparent background.
Tip: If you only have a JPEG, we can often convert it and clean it up as part of our free artwork check. Just let us know when you order.
Resolution Guide
| Use Case | Resolution Needed | Suitable For |
|---|---|---|
| Web/social media | 72 dpi | Screen only, not for print |
| Standard digital print | 150 dpi | Acceptable but not ideal |
| Print minimum | 300 dpi | Recommended for all garments |
| High-detail DTG print | 400 dpi | Photorealistic prints |
| Large format (A2+) | 150 dpi at final size | Banners, signage |
Always check the dpi at the actual print size, not the file size on screen. A file that looks sharp at thumbnail size may be only 72 dpi when expanded to a chest print.
Colour Mode: CMYK vs RGB
Screens display colour in RGB (Red, Green, Blue). Printers reproduce colour in CMYK (Cyan, Magenta, Yellow, Black). These are different colour models and the conversion between them can shift vibrant colours, especially bright greens, oranges and electric blues.
For the most accurate results, set your artwork to CMYK before you send it. If you design in RGB and we convert it for you, some colours may appear slightly different on the final garment. This is particularly relevant for DTG printing, which uses a four-colour inkjet process.
For DTF printing, we print to a transfer film first and colours tend to stay very close to the RGB original, but CMYK files are still preferred.
Print-Ready Artwork Checklist
Before submitting your file, run through this quick checklist:
- Resolution is 300 dpi minimum at the intended print size
- Background is transparent (PNG or AI/EPS), not white
- Colour mode is CMYK (or flag it as RGB so we can check)
- All fonts are outlined or embedded (prevents font substitution)
- Bleed and safe zone are set for any edge-to-edge designs
- File is named clearly with your order reference or garment colour
Free Artwork Setup at Printing Planet UK
Not a designer? No problem. Printing Planet UK offers a free artwork check with every order, and we can handle basic setup adjustments at no extra charge. If you need a full design from scratch, ask us about our design service starting from £25.
Whether you are ordering one custom t-shirt or 500 pieces, getting the artwork right from the start means your order arrives exactly as you imagined it.
For more help before you order, read our guides on custom t-shirt design, choosing the best fonts for t-shirt designs and the differences between DTF and DTG printing methods. You can also go straight to ordering custom clothing online when you are ready.
Ready to place your order? Visit us at Putney SW15 3BD or call 020 3669 9854 to speak to the team. Upload your artwork when you order and we will do the rest.