Barcode Inspection: Ensuring Accuracy and Traceability

What is Barcode Inspection?

Barcode inspection is the evaluation of the accuracy, readability, and compliance of printed barcodes against industry standards, maintaining product traceability throughout the supply chain and regulatory compliance. This quality control process involves assessing key parameters, such as symbol contrast, print quality, size accuracy, and environmental durability, to ensure reliable scanning throughout the supply chain.

Importance

Barcodes transformed how companies manage inventory and assets, providing a machine-readable way to encode product, serial, and batch numbers. By automating the labor-intensive and error-prone manual data entry, the entire supply chain—from product Quality Assurance and Control (QA & QC) to last-mile delivery—is greatly enhanced.

Because it’s such a vital element in most industries, barcode inspection is a key requisite for the following reasons:

• Ensures scan accuracy and efficiency – Damaged barcodes disrupt product inspections. Consistent verification and validation ensure accuracy, preventing manual workarounds.

• Optimizes production and reduces waste – Reviews and tests on tracking labels provide feedback, enabling early corrections, halting faulty printing, and reducing material waste.

• Maintains supply chain integrity and traceability – Barcodes are the supply chain’s backbone. Inaccurate ones cause companies to lose operational visibility and control.

• Supports regulatory compliance – Sectors like healthcare, Food & Beverage (F&B), and automotive face strict labeling laws. Routine verification is critical for full compliance.

• Prevents costly errors and chargebacks – Inaccurate or unreadable barcodes cause expensive problems like incorrect shipments, inventory discrepancies, and product recalls. Regular inspection avoids these.

Types of Barcodes and Their Common Issues

The diversity of barcodes available today stems from the varied data, tracking, and compliance needs across different industries. Understanding the distinctions helps businesses choose which suits their operations best and address any problems they may encounter during real-time barcode inspection.

1D Barcodes

Also known as linear codes because they store data horizontally, they are widely used for product identification and inventory tracking in retail warehousing, logistics, and healthcare (e.g., medication labeling). Common issues include the following:

• Print quality issues (faded or blurred lines)

• Limited data storage (only numeric or alphanumeric codes)

• Requires a larger space for more information (e.g., product ID, batch number, expiration date, etc.)

Among the most common 1D barcodes in use today are European Article Number (EAN), Code 25, International Standard Book Number (ISBN), GS1-128, and Codabar.

2D Barcodes

These two-dimensional codes use patterns (e.g., squares, dots, hexagons) to store data horizontally and vertically. They are ideal for large data volumes, especially in manufacturing, pharmaceuticals, F&B, and marketing. Most frequent problems are:

• Smudging or distortion

• Damage to any portion may corrupt data

• Requires camera-based scanners, often incompatible with basic barcode readers

Prominent examples of 2D barcodes commonly deployed include Quick Response (QR) code, PDF147, Data Matrix Aztec Code, the Girocode, and the Royal Mail Mailmark.

Composite Barcodes

As the name suggests, this barcode combines a 1D linear barcode (typically GS1-128) with a 2D component. This hybrid design provides human-readable and detailed product data, making it the preferred choice for real-time product verification and serialization in inventory and distribution, particularly in pharmaceuticals, medical devices, and food traceability. However, certain issues can arise:

• Quality degradation

• Higher printing complexity

• Requires advanced scanners for full data capture

Key Criteria for Verifying and Validating Barcodes

Barcodes are the backbone of product identification, traceability, and supply chain efficiency. Careful verification (quality measurement) and validation (data accuracy) are equally crucial; don’t overlook either. Consider these attributes:

Validation Checks

• Data accuracy ensures the barcode correctly links to the right product information in the database.

• Data format compliance, using correct application identifiers, is crucial for supply chain interoperability.

• Readability across devices ensures consistent scanner performance, allowing all partners to access validated data regardless of scanner type.

Verification Graders

• Print contrast refers to the difference in reflectance between the dark bars and light spaces. Poor contrast may cause scanner misreads.

• Decodability measures a scanner’s accuracy in interpreting encoded data, ensuring minimum readability.

• The quiet zone is the essential blank space around the barcode, preventing misreads by separating it from other elements.

• Symbol contrast modulation refers to contrast variation across the barcode, preventing incorrect partial reads and data alteration.

• Print defects, like spots, voids, or smudges, can cause scanners to misinterpret data.

Barcode Inspection Process

This easy-to-follow barcode inspection system helps prevent product misidentification, shipment delays, and expensive recalls. Although designed with product traceability in mind, it’s customizable for applications like asset tagging or maintenance tracking.

Step 1: Establish barcode specifications and compliance requirements.

Ensure barcodes meet industry and regulatory standards, are compatible with the systems of supply chain partners, and can withstand handling or storage conditions. These are some standards to consider:

• ISO/IEC 15416 & 15415 for print quality of linear and 2D barcodes, respectively

• GS1 (General Specifications) for global trade

• Food and Drug Authority (FDA)’s Unique Device Identification (UDI) for medical devices

Step 2: Generate and validate barcode data integrity.

Generate barcodes using Enterprise Resource Planning (ERP), Manufacturing Execution System (MES), or labeling software. Perform validation to confirm that the following encoded data is accurate and corresponds to the right product record:

• Product identification

• Serial number

• Batch or lot number

• Expiration, best by, and manufacture date

• Application identifiers

• Country of origin or manufacturing location

• URLs or digital links (especially for 2D barcodes)

Step 3: Conduct pre-print quality verification.

Print a test label and verify it with a barcode verifier, meticulously checking contrast, quiet zones, symbol modulation, and print density. This step prevents the mass production of defective barcodes, saving costs and avoiding operational disruptions.

Step 4: Perform post-print barcode quality check.

Inspect printed barcodes directly on product packaging or labels using scanners to ensure they meet quality standards. This step typically includes durability tests, particularly for products that are exposed to harsh environments.

Step 5: Integrate in-process and end-of-line scanning.

Continuously read barcodes using automated scanners during production or packaging to detect unreadable or incorrect ones in real time. Doing this prevents defective products from entering the supply chain.

Step 6: Document and analyze barcode inspection results.

Record and analyze inspection data to track trends, identify recurring issues, and improve printing processes. Don’t let recurring defects go unnoticed as they will lead to higher rejection rates and undetected compliance issues.

Step 7: Implement appropriate corrective and preventive actions.

Consistent barcode quality is achieved by identifying and addressing underlying causes, such as printer calibration issues or the use of inappropriate label materials. Proactive prevention of recurrence mitigates operational inefficiencies and reduces product waste.

Barcode Inspection in Manufacturing Environments

Inspecting barcodes varies across industries due to unique considerations, such as operational demands, environmental factors, and regulatory requirements. These are some points to consider: