CMYK vs RGB: Why It Matters
Every screen — your phone, laptop, and monitor — displays colours using RGB (Red, Green, Blue), which creates colours by mixing light. Printers, however, use CMYK (Cyan, Magenta, Yellow, Key/Black), which creates colours by mixing ink on a physical surface. These are fundamentally different colour systems, and not all RGB colours can be reproduced in CMYK.
Bright neon greens, electric blues, and vivid purples that look stunning on screen often appear duller or shifted when printed. This is not a printing error — it is a physical limitation of ink-based reproduction. The range of colours a system can produce is called its gamut, and the CMYK gamut is smaller than RGB.
What This Means for Your Design
- Always design in CMYK colour mode if possible
- Avoid relying on extremely vivid or neon colours — they will shift in print
- Use your printer or designer tool s CMYK soft-proof feature to preview how colours will look when printed
- Pure black in CMYK is C:0 M:0 Y:0 K:100. For a richer, deeper black, use C:40 M:40 Y:40 K:100 (known as rich black)
What Is Bleed?
Bleed is the area of your design that extends beyond the final cut line. It exists to prevent white edges appearing on your finished sticker if the cutting is fractionally off-centre — which is normal and expected in all printing processes.
Standard bleed for sticker printing is 3mm on all sides. This means if your finished sticker is 50mm x 50mm, your artwork file should be 56mm x 56mm (50 + 3mm bleed on each side).
How to Add Bleed
- Extend any background colours, patterns, or images to fill the full bleed area
- Do not place important text or logos in the bleed zone — they may be partially cut off
- If using our online designer, bleed is handled automatically — you just design within the safe zone
Cut Lines Explained
The cut line (also called a die line or cut path) defines the exact shape your sticker will be cut to. It is not printed — it is a guide for the cutting equipment.
Types of Cut
- Die-cut: Cut to a custom shape that follows your design. The most professional option — the sticker shape becomes part of the design.
- Kiss-cut: Cut through the vinyl but not through the backing paper. The sticker remains on a larger backing sheet for easy peeling. Common for sticker sheets.
- Rectangle/Square cut: The simplest cut — straight lines. Cheapest to produce.
- Circle/Oval cut: Clean, professional shape. Popular for logo stickers and product labels.
- Custom contour: The cut line follows the outline of your design with an offset margin. Creates a professional die-cut effect.
Safe Zone
The safe zone is the area inside the cut line where all critical content should be placed. The standard safe zone is 3mm inside the cut line. Any text, logos, or important design elements should be within this zone to ensure they are not affected by cutting tolerances.
Think of it as three concentric zones:
- Bleed zone (outermost): Background fills, extends 3mm outside the cut line
- Cut line: The actual cutting path
- Safe zone (innermost): Critical content, 3mm inside the cut line
Resolution and DPI
DPI (Dots Per Inch) measures the detail level of your artwork. Higher DPI means sharper, more detailed print.
- 300 DPI: The standard for professional print quality. Text is sharp, images are detailed, and gradients are smooth.
- 150 DPI: Acceptable for large-format stickers (200mm+) viewed from a distance, but text may appear slightly soft.
- 72 DPI: Screen resolution only. Not suitable for print — images will appear pixelated and blurry.
When preparing artwork, ensure all images are at least 300 DPI at the final print size. A photograph that looks sharp on screen at 72 DPI will print at roughly one-quarter the expected size at 300 DPI quality.
White Ink in Sticker Printing
Standard CMYK printing cannot produce white — it relies on the white of the vinyl surface showing through. When printing on clear, coloured, or metallic materials, a separate white ink layer is needed.
White ink is printed first as an opaque base, then the CMYK artwork is printed on top. This ensures colours appear vivid and true, rather than being affected by the material beneath.
In professional print files, the white ink layer is specified as a spot colour (typically called RDG_WHITE or White) on a separate layer from the CMYK artwork.
File Formats for Sticker Printing
Best Formats
- PDF (vector): The gold standard. Preserves text as editable vectors, supports CMYK, and includes bleed and crop marks. If you have access to Adobe Illustrator, InDesign, or Affinity Designer, export as PDF/X-4.
- SVG: Good for vector graphics and logos. Scalable without quality loss.
- PNG (300 DPI): Best raster format for stickers. Supports transparency for die-cut shapes.
Acceptable Formats
- JPG (300 DPI): Suitable but no transparency support. Best for rectangular stickers with solid backgrounds.
Not Recommended
- GIF, BMP, TIFF: Limited colour support, large file sizes, or compatibility issues.
- Word/PowerPoint: Not suitable for professional printing — limited colour control and resolution.
Using Our Online Designer
If you do not have design software, our free online sticker designer handles all of the technical details automatically. The designer works in CMYK colour space, adds the correct bleed, shows the cut line and safe zone, and exports a print-ready PDF with vector preservation. You can upload images, add text, create patterns, and preview your design in a CMYK-accurate soft proof before ordering.