Barcodes in Engineering: QR, DataMatrix and Linear Codes Explained

Before you decide on a format, it helps to separate barcodes into two main families: 1D (linear) codes and 2D (matrix) codes. Each has strengths in different engineering scenarios.

Common 1D symbologies in engineering

• Code 128 – high density linear barcode that encodes the full ASCII character set. Common on logistics labels, racking and internal asset labels where there is enough label length.
• GS1-128 – uses the Code 128 symbology but follows GS1 standards with Application Identifiers for fields such as serial, batch and dates. Widely used when items move through multi company supply chains and must remain globally unique.
• Code 39 – older industrial symbology still seen on legacy labels and some military or aerospace specifications. Easier to decode but less space-efficient than Code 128.

Linear barcodes remain a good choice when labels can be longer, you want very fast scans and existing processes already rely on 1D scanners.

A QR code is a square grid with three large finder squares in three corners and timing patterns that make it easy to detect and read from almost any angle. Almost every modern smartphone can scan them using the built-in camera, which makes them extremely useful where people and phones are central to the workflow.

QR codes include error correction so they can remain readable even if partially damaged. However, they are usually physically larger than equivalent DataMatrix symbols for the same data, and the finder squares consume space. On very small tags or parts, that can become a constraint.

In practice, QR works best where you want human-friendly, phone-friendly interaction and have a bit more room on the label.

A DataMatrix code is another 2D symbol, typically square, built from small black and white cells. Its visual hallmark is the solid L-shaped finder pattern on two adjacent sides, with the other two sides formed from alternating modules.

DataMatrix is defined in ISO/IEC 16022. GS1 DataMatrix is mandated or recommended in several regulated sectors, for example pharmaceuticals, for product serialisation and traceability.

Typical DataMatrix applications

• Direct part marking on small components, PCBs and electronic assemblies.
• High-density labels in congested panels or equipment bays.
• Small stainless steel or Fox-Flo® asset tags where traceability must last for years.
• Regulated environments that demand long term, machine-readable identification.

In short, DataMatrix is often the best fit when the asset is small, the environment is tough and you need reliable traceability over many years.

Despite the rise of 2D symbols, linear barcodes remain extremely useful and often the simplest answer for straightforward asset IDs and logistics tasks.

Code 128 and GS1-128 in practice

• Code 128 – excellent for internal numbering schemes such as asset IDs, location codes or work order labels, and very fast to read in stores or logistics processes.
• GS1-128 – ideal when you need structured, multi-field data (serial, batch, expiry dates) that is machine readable in any organisation that understands GS1 Application Identifiers.

Typical linear barcode applications include:

• Warehouse and spares management.
• Racking and bin locations.
• Simple assets where a single ID is enough and there is room for a longer symbol.

Where GS1 rules apply but a 2D symbol is preferred, you will often see GS1 DataMatrix on small products or components that need serialised identification, and GS1 QR when you want GS1 structured data in a smartphone-friendly format.

There is no single “best” symbology. The right choice depends on the asset, the environment and how your team will scan and use the data.

1. 1

   Size and mounting

   Very small assets or tight label spaces usually favour DataMatrix. Medium to large labels where human interaction matters often suit QR codes®. Long labels on trays, racks or large equipment are ideal for linear codes like Code 128 or GS1-128.

2. 2

   Scanners and users

   Smartphone-first workflows point towards QR. Industrial scanners and fixed readers usually support 1D, QR and DataMatrix, but always confirm what your installed devices can read. In many factories and process plants, DataMatrix is the default for machine vision and direct part marking.

3. 3

   Data model and structure

   If you only need a single ID that points to a database record, any symbology can work. When you need structured machine-readable data in the symbol, GS1-128, GS1 DataMatrix or GS1 QR are strong candidates.

4. 4

   Lifecycle and environment

   Outdoor and long-life infrastructure may combine rugged materials such as Fox-Flo® with DataMatrix for core identification and QR for richer information. Indoor data centres and switchrooms may rely mainly on QR or Code 128 for rapid scanning during audits.

Getting the symbology right at specification stage avoids years of workarounds, confusion and expensive rework.

Silver Fox® does more than manufacture labels. The focus is on helping engineers design identification systems that work in the field – combining materials, printing systems and training.

If you want to avoid barcode headaches later in the asset life cycle, it pays to get the choice right at the start. The right mix of QR, DataMatrix and linear barcodes makes identification simpler, more robust and easier to maintain over time.

Silver Fox® can help you select symbologies, choose materials, configure Fox-in-a-Box® and Labacus Innovator®, and train your team so they can specify and use barcodes with confidence.