Anatomy of the Perfect Barcode

 In 201

My mother always admonished my siblings and me that people would listen and learn more from a positive message than from a negative one. I hope she will forgive me for taking several years before writing this article about the perfect barcode. Horrible barcodes are so much more—interesting.THE PERFECT UPC Cropped

But a truly perfect barcode is also interesting because it is so rare. And yes, Mom, I admit, a perfect barcode can teach us much. The owner of this package can be proud and we are holding nothing back by disclosing it in all its barcode beauty.


I will preclude you purists from pointing out the obvious from the verification report—yes this is not actually the perfect barcode. But it is very, very good. The 10 scan average grade is an ISO 3.9, a near-perfect ANSI A.  The Average Bar Gain is an insignificant -1% of the tolerance.

040XITF White Report

The perfect barcode would earn the highest percentage grade for each ISO parameter—this symbol doesn’t quite accomplish that. To earn an ANSI A, Symbol Contrast must be 70% or greater, so this symbol can be considered a “low A”. The threshold for an A in modulation is also 70%; at 85%, it is a solid “high A”. The A threshold for Defects is  ­<15%; again a solid high A; decodability is far better than the > 62% threshold and the remaining parameters are Pass/Fail.



While the Scan Reflectance Profile is not a great diagnostic tool, it is a thing of beauty on a near-perfect barcode. Look and marvel:

Perfect UPC SRP Window



Here’s what you should be looking for:

  • the Northern hemisphere is incrementally nearly identical to the Southern hemisphere
  • the light reflective “peaks” of all spaces, narrow as well as wide, are nearly equal to each other
  • the dark reflective “valleys” are likewise nearly equal to each other
  • the light reflectance value of the left and right quiet zones are nearly identical
  • the “peak” and “valley” transitions (which are the edge definition) are mostly not serrated
  • no single bar or space even comes close to failing to penetrate the Global Threshold

The Scan Reflectance Profile of a near-perfect barcode can be summarized in just one word: symmetry.

Another important attribute is the un-truncated, full-height symbol and the consistent verification results throughout the vertical redundancy of the symbol.

What can we learn from this? For one, we can learn that this is an achievable result even on a lowly generic package. In many ways this is an example of “less is more” because it is such a simple, straightforward image. Frequently the problem barcodes that come through the lab here at Barcode-Test are very high end, expensive labels and packaging with exotic metallic colors and expensive laminates.

We don’t always have a lot of choice what our barcodes look like—our customers usually determine that. But to the extent possible, you now know what you want your verification report to look like.

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