No Virginia, there are no 3D barcodes but we hear them referred to quite often. It is a common misconception, so let’s be clear: Data Matrix Code and QR Code are 2D barcodes, and UPC and Code 128 1D barcodes). Come on people, remember your middle school geometry: data encoded in the X or Y axis only is a 1D barcode; data encoded in both X and Y are 2D barcodes. If data can be encoded in the X, Y and Z axis, that would be a 3D barcode. Clear?
Unicorns, Satyrs and 3D Barcodes
There are some symbol types that have a second tier of data encoding. The venerable UPC actually does this. Unbeknownst to most people, there are two character sets for the manufacturer portion of a Version A UPC. Let’s call them Character Set A and B. By arranging the six digits of the manufacturer ID in a particular pattern, a 7th digit can be encoded. Did you know that all Version A UPC symbols encode 13 digits? It’s true. But this does not make it a 3D barcode.
Tier 2 Barcodes are not 3D
Denso, QR Code inventor and owner of the patent, has recently released a secure version of QR Code, called SQRC. This clever development allows some of the data in a QR Code to be available to anyone with a scanner. Someone with authorized access can scan the same QR Code and access an additional layer of secure data. But like a Version A UPC, this is not a 3D barcode.
The very special Aztec Code resembles a Data Matrix barcode, with multi-colored squares arrayed in a rectangular pattern. The color pattern encodes additional information beyond what the squares themselves encode. But this is not a 3D barcode. We call them Tier 2 barcodes.
Marking a part or sub-assembly with laser, an acid etch or a mechanically imposed peen is called Direct Part Mark or DPM. It will disrupt the substrate and technically create a Z axis. But the vertical dimension carries no intelligence and therefore, DPM is not a 3D barcode.
Reference to a 3D barcode is a misnomer. It is innocent incorrect speech. A true 3D barcode would resemble 3D checker or chess, and while that could give it impressive data storage capacity, how could it me imaged in print? Perhaps a holograph–someday?