The basic corrective actions for matrix barcodes are similar to those discussed in Part 2 of this series, which covers this topic for linear barcodes. You may wish to read that article, as we will not repeat the commonalities here. There are some important differences both in ISO print quality and industry application data structure.

Matrix Barcode Print Quality

Matrix or 2D barcodes differ from linear or 1D barcodes in several ways. Although in both cases the substrate is moving during the printing process, the motion only affects the image in the direction of travel. The image of a linear barcode will be impacted either in line with the orientation of the bars and spaces, or perpendicular to it. If the printer is running at high speed, the bars could be somewhat wider than nominal if they are oriented perpendicular to the direction of travel. If the bars are in line with the direction of travel, only the height of the bars will be impacted.

A matrix barcode encodes information on two axes, so high speed travel in the printing process will impact it in one direction. The square elements may be elongated into rectangles, which will downgrade one or more print quality parameters.

Quiet zones which are correspondingly smaller in matrix codes will also be impacted.

Barcode Design

We did not touch on barcode design files on Part 2, so we will do so here. The design file is where  compensation for gain can be made. This compensation is commonly called bar width reduction. This is a one-axis adjustment in line width for linear barcodes, but a two axis adjustment for matrix barcodes. Furthermore, if printer travel speed is a factor, the line-of-travel compensation may be different than the perpendicular compensation.

Data Structure

There are many industrial applications for barcodes. Barcodes for aerospace applications have different data field attributes and prefixes than healthcare, defense and other barcode applications. A generic data matrix code is structurally different from a GS1 Data Matrix code. Adding to the confusion, the human readable information is not repeated verbatim in the encoded information in the barcode. This is a common but devastating mistake. A perfectly printed barcode with structural errors will fail just as surely as a poorly printed, perfectly structured barcode.

Barcodes in retail and other end-user situations differ from barcodes in distribution. The bar widths for barcodes on inner cartons and master cartons are much wider than barcodes on consumer-level primary packaging.  A verifier will fail a barcode if the bar widths violate the relevant industry application.

Verification

An ISO compliant barcode verifier is the best way to test and grade a barcode for ISO print quality and industry application data structure. The verification report will indicate what ISO parameters and/or industry application attributes are downgrading the barcode. This pinpoints the necessary corrective actions.

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3db Barcode Testimonial

Our company (an advanced software company) recently worked with Barcode Test to source a barcode verifier.  Not long ago, we were awarded a contract requiring products to be marked with IUIDs in accordance with MIL-STD-130.  For that standard, marking labels must pass a verification test that evaluates many variables (contrast, size, clarity, syntax, modularity, and more).  After a thorough search, we reduced our options to a select few.

In our search for a verifier, the Axicon line caught our attention.  Barcode Test is our regional reseller for this product.   From the beginning, they were very prompt with their responses.  We ended up having a quick call with John Nachtrieb to go over our needs.  John was extremely easy to work with and provided a lot of great information.  He was very knowledgeable on the matter and was quick to offer up a demo unit (free of charge).

Upon receiving the demo verifier and testing it, a few questions arose.  John joined a call with us and answered all our questions.  Ultimately, the Axicon verifier wasn’t the best fit for us, so we shipped the demo back.  John was completely understanding.  A few weeks later, Barcode Test reached back out with another possible verifier for us to try.  While they didn’t sell that brand, they just wanted to help us find the best option that met our needs. They even offered to send us the unit that they have in-house to see if it worked to our liking. 

Barcode Test is truly a great company to work with.  Their service and willingness to help the customer are far beyond what you typically get from other companies.  They are experts in barcode quality assurance and seem willing to help in any way they can (even if that means not getting a sale and recommending another option that better fits the customer’s needs).  If anyone is in the market for barcode verification/scanning services or products, I would highly recommend giving Barcode Test a call.

Regards,

Production Manager