Barcode Guide · EAN-13, QR, ITF-14, GS1-128

A barcode failure discovered at retail scanning, or worse, at a retailer's goods receipt system, is one of the most costly pre-press errors in packaging production. A full production run of packs may need to be relabelled or reprinted. Understanding which barcode type applies to which product, and what the print specifications are for each, prevents this failure entirely.

EAN-13 magnification · the size range

EAN-13 is not produced at one fixed size. It has a defined magnification range, a percentage of the nominal (100%) size. The nominal size is called the reference size and has specific dimensions. Magnification is expressed as a percentage of this reference.

EAN-13 key rules

• Always produce from GS1-certified barcode software, do not create barcodes in Illustrator or Photoshop using font-based methods. Use dedicated barcode software (Barcode Studio, Tec-It, Bar-One, or the barcode module in packaging software like ArtiosCAD or Esko DeskPack). Font-based barcodes frequently have incorrect bar widths.
• Always include the human-readable number below the barcode in OCR-B font. The human-readable number allows manual entry if the barcode is unreadable. The check digit (last digit) must be included.
• Never truncate the height, reducing the height below the GS1 specification reduces scan reliability. Scanners sweep horizontally across the bars and need the full height to guarantee a complete scan.
• The first digit is printed to the left of the barcode, not inside the bar area. This is a specific EAN-13 layout requirement. The number system character appears to the left of the left guard bars.

QR (Quick Response) codes are two-dimensional matrix barcodes that encode URLs, text, payment information, or any alphanumeric data. They are widely used on Indian packaging for consumer engagement, linking to product websites, UPI payment, nutritional information, authenticity verification, and promotional content. A QR code is not a replacement for EAN-13 at retail checkout, both serve different functions and most retail packs carry both.

QR code minimum sizes for packaging

QR code error correction levels

QR codes have four error correction levels that determine how much of the code can be damaged or obscured while remaining scannable. Higher error correction means more data redundancy, and a denser, more complex matrix that requires better print quality to scan reliably.

• Level L (Low): 7% of data can be restored. Smallest and simplest matrix. Use only where print quality is excellent and the code will not be physically damaged.
• Level M (Medium): 15% recovery. The most common choice for packaging. Good balance between matrix complexity and damage tolerance.
• Level Q (Quartile): 25% recovery. Use where the code may be partially covered or damaged, outdoor applications, flexible packaging that may crease.
• Level H (High): 30% recovery. Required when a logo is placed inside the QR code (logo replaces part of the data, error correction compensates). Also for rough or textured substrates.

ITF-14 (Interleaved Two-of-Five, 14 digits) is the barcode used on outer shipper cases and transit packaging. It is scanned at warehouse receiving, distribution centre, and retail back-of-house operations, not at retail checkout. The ITF-14 number is derived from the EAN-13 of the contained product by adding a packaging indicator digit at the front.

ITF-14 key specifications

ITF-14 on corrugated board · special requirements

Corrugated board is printed by either flexography (directly on the corrugated liner, post-print) or by printing a flat liner sheet which is then laminated onto the corrugated board (pre-print). The two methods have different printing characteristics:

• Pre-print (high-quality liner printing): Better dot quality, finer bar reproduction. ITF-14 can be printed at 100% magnification reliably. Use the standard ITF-14 specifications.
• Post-print direct (flexo on corrugated): Lower quality, the corrugated flutes create a washboard effect on the printed surface. ITF-14 should be at minimum 125–150% magnification. Bars should run parallel to the corrugation direction (horizontally), not perpendicular. The washboard effect is worst in the bar direction when bars cross corrugation ridges.

GS1-128 (formerly UCC/EAN-128) uses Application Identifiers (AIs) to encode structured data beyond just the product number, including batch/lot number, expiry date, serial number, weight, and other logistics information. It is the standard barcode for supply chain labels, pharmaceutical secondary packaging, and any application requiring structured variable data.

Application Identifiers · the key to GS1-128

Every data field in a GS1-128 barcode is preceded by a two or four-digit Application Identifier in parentheses that identifies what the following data means. Common AIs used in Indian packaging:

GS1-128 size specifications

GS1-128 bar height minimum is 32mm. Width depends on the data encoded, more data fields produce a wider barcode. The X-dimension minimum is 0.250mm. For most label and carton applications at reasonable data content, a GS1-128 barcode will be 60–120mm wide. Always generate and measure the actual barcode after encoding the required data before approving the artwork, do not assume a fixed width.

Retail barcode scanners use a red laser (633–680nm) or LED red light to read barcodes. The scanner measures the difference in light reflectance between bars and spaces. Bars must absorb the red light (appear dark to the scanner). Spaces must reflect the red light (appear light to the scanner). Any colour combination that does not provide sufficient reflectance contrast at red wavelengths will cause scan failure, regardless of how well the barcode looks to the human eye.

The reflectance rule

The key principle: colours that appear dark to the human eye are not necessarily dark to a red laser scanner. Cyan ink, for example, appears dark blue to the eye but reflects red light strongly, making it appear almost white to the scanner. A barcode printed in cyan bars on a white background will fail to scan despite looking high-contrast to the human eye.

A quiet zone is the blank, unprinted area that must surround a barcode on all required sides. The scanner uses the quiet zone to identify where the barcode starts and ends, without it, the scanner cannot locate the barcode boundaries and will fail to decode. Any printing, design element, text, or colour change within the quiet zone risks causing a scan failure.

Quiet zone violations · the most common cause of retailer rejection

The quiet zone is violated more often by design choices than by barcode placement errors. Common violations: the barcode is placed too close to the pack edge (fold line or trim edge encroaches on quiet zone), a design element such as a wave, shadow, or gradient extends into the quiet zone, the human-readable text wraps around and intrudes into the left quiet zone, or the barcode is placed on a panel that has a colour or pattern change within the quiet zone boundary. Check quiet zones by measuring from the outer edge of the outermost bar, not from the barcode border in the software, which may be set differently.

Barcode verification is the process of using a calibrated verification instrument to measure the quality parameters of a printed barcode and produce a grade against the ISO/IEC 15416 standard (for linear barcodes) or ISO/IEC 15415 (for 2D barcodes including QR). A verification grade tells you with scientific precision whether the barcode will scan reliably across all retail and logistics scanning environments, not just on the one scanner you tested it with.

Why smartphone scanning is not verification

Testing a barcode by scanning it with a smartphone is the most common and most dangerous shortcut in Indian packaging production. A smartphone scanning a barcode tells you only that this particular phone, at this particular angle and distance, in this particular lighting condition, successfully decoded this barcode. It tells you nothing about whether the barcode will scan on the specific fixed-beam laser scanners at Reliance, D-Mart, or Big Bazaar checkout counters, or on the omnidirectional scanners at a distribution warehouse. A barcode can scan perfectly on a smartphone and fail consistently on a retail scanner. The only reliable test is a calibrated verification instrument.

ISO 15416 verification grades · what they mean

When to verify · the production verification protocol

• Pre-production artwork check: Verify the barcode in the digital artwork using barcode software quality checking, not full ISO verification, but catches gross errors in bar width, check digit, and structure.
• Press proof verification: Verify the barcode on the printed proof using a calibrated verifier before approving plates. Minimum acceptable grade: B. Any grade below B requires investigation and correction.
• Production sample verification: Verify a sample from the production run within the first 1,000 impressions. If grade drops from proof to production, investigate immediately, do not run the full production before resolving.
• Flexo and gravure jobs: Verify every colour change and substrate change separately, barcode quality varies more with process variables in flexo and gravure than in offset.

• Always generate barcodes in dedicated barcode software, never in Illustrator, InDesign, or Photoshop using fonts or manually drawn bars. Dedicated software (Tec-It TBarCode, Bar-One, Barcode Studio, Esko DeskPack barcode module) generates mathematically correct bar widths and validates check digits automatically.
• Export barcodes as vector EPS or PDF, never as raster images (JPEG, PNG, TIFF). Raster barcodes are subject to scaling and resolution issues. A raster barcode exported at 300 PPI and then scaled in InDesign changes its effective bar widths. Vector barcodes scale cleanly to any size without quality loss.
• Place barcodes in the artwork at the specified magnification, do not scale the placed barcode in InDesign or Illustrator after placing it. Set the magnification in the barcode software before generating the EPS, then place it at 100% in the layout. Scaling after placement changes bar widths unpredictably.
• Set barcode bars to 100% black only (C0 M0 Y0 K100), never set bars to a CMYK mix or spot colour unless the press room has confirmed the alternative ink will provide sufficient reflectance contrast. Rich black and composite blacks can change the reflectance characteristics of bars.
• Set barcode spaces and quiet zones to 0% of all inks, the space between bars and the quiet zone must be completely unprinted. Tints, gradients, or background colours in the quiet zone area will cause scan failures.
• Set barcode elements to overprint: NO, barcodes must knockout all underlying elements. An overprinting barcode places bars over background colour, the combined colour changes reflectance characteristics and may cause scan failures.
• Mark the barcode layer clearly in the file, label the layer "Barcode, do not trap, do not modify." Add a note to the file for the pre-press team. Automatic trapping applied to barcode elements can change bar widths and cause scan failures.