Why Barcodes on Labels Matter
Barcodes and QR codes are functional elements that must scan reliably every time. A barcode that fails to scan at point of sale causes delays, customer frustration, and potential lost sales. Understanding the technical requirements for printed barcodes ensures your labels work as intended.
Common Barcode Types
EAN-13 / UPC-A
The standard retail barcode used worldwide. Required for any product sold through retail channels. Consists of 13 digits (EAN-13) or 12 digits (UPC-A). You need a GS1 membership to obtain legitimate barcodes for retail sale.
Code 128
A versatile barcode used in logistics, shipping, and inventory management. Can encode any ASCII character. Common on shipping labels and warehouse systems.
QR Codes
Two-dimensional codes that store URLs, text, contact information, or other data. Increasingly used on product labels to link to websites, ingredient lists, instructions, or promotional content. Can store significantly more data than traditional barcodes.
Data Matrix
A 2D barcode used in industrial and pharmaceutical applications. Very compact — can encode data in a small space. Common on medical device labels and electronic components.
Printing Requirements
Minimum Size
- EAN-13: Minimum 80% of nominal size (approximately 26mm x 18mm). Standard size is 37.29mm x 25.93mm.
- QR Code: Minimum 15mm x 15mm for reliable scanning. 20mm+ recommended for consumer use.
- Code 128: Variable width depending on data length. Minimum bar height 5mm.
Quiet Zones
Every barcode requires a clear margin around it called the quiet zone. This empty space allows scanners to detect where the barcode starts and ends. Minimum quiet zones:
- EAN-13: 3.63mm left, 2.31mm right
- QR Code: 4 modules (approximately 2-3mm at typical sizes)
- Code 128: 10x narrow bar width on each side
Colour and Contrast
Barcode scanners read the contrast between dark bars and light spaces. For reliable scanning:
- Best: Black bars on white background (maximum contrast)
- Acceptable: Dark blue, dark green, or dark brown bars on white or light yellow
- Avoid: Red bars (many scanners use red lasers and cannot read red), light colours on light, or dark on dark
- Never: Barcodes on metallic or reflective surfaces without a white ink base
Resolution
Barcodes must be printed at sufficient resolution for clean, sharp edges on the bars. Minimum 300 DPI is required. Lower resolution causes fuzzy bar edges that can cause scan failures.
QR Code Best Practices
- Test before printing: Scan your QR code with multiple devices and apps before ordering
- Use a short URL: Shorter data produces a simpler, more scannable QR code
- Error correction: Use Level M (15%) or Level Q (25%) error correction for labels that may get scuffed
- Add a call to action: QR codes without context are ignored. Add text like Scan for ingredients or Scan for 10% off
- Maintain contrast: Dark modules on a light background. Custom-coloured QR codes are possible but must maintain minimum contrast ratios
Material Considerations
- White vinyl: Ideal for barcodes — excellent contrast, durable, waterproof
- Clear vinyl: Barcodes need a white ink background behind them for scanning
- Metallic vinyl: Barcodes need a white ink base — reflective surfaces cause scan failures
- Matte vs gloss: Both work well. Matte reduces glare that can occasionally interfere with scanning under bright lighting
Generating Barcodes
StickerNation s online designer includes a built-in barcode generator supporting EAN-13, UPC-A, Code 128, QR Code, and Data Matrix formats. Enter your data and the generator creates a print-ready barcode at the correct resolution and proportions. The barcode is placed directly on your label design within the editor.