If you are producing any kind of product with a barcode printed on it, you may have heard of barcode grading. The aim of the process is actually simple enough, in that it is designed to test the quality of barcodes, and how easily they can be scanned. However, the process through which this is assessed is quite a complex one, and a number of different factors are tested, and this makes producing reliable barcodes somewhat difficult.
Unless, that is, you know what barcode graders are looking for. Today, I’ll go through the requirements for various types of barcode, and then discuss how to reliable produce good ones.
The Grades
First, the basics. Barcodes are graded according to a system of letters, just like in school. The best will be graded an A, and the worst an F. However, when each code is tested, a number of different features are looked at — I will describe these shortly — and the grade for the barcode is based on the WORST score it got. So if, on one parameter, it scored an F, even if all the other grades are As, it will still get an F.
Typically, when barcodes are tested the grades from a large number of the same batch of barcodes is graded, and an average grade produced, in order to even out any errors in manufacturing.
The Parameters
The parameters measured when grading barcodes are determined by ISO / ANSI standards, and depend on the type of barcode being tested. For a 1D linear barcode, the most common type, the parameters tested are:
- Edge Determination
- Minimum Reflectance
- Symbol Contrast
- Minimum Edge Contrast
- Modulation
- Defects
- Decode
- Decodability
- Quiet Zone
For multi-row stacked barcode grading, the same parameters are tested, except that each will be measured on each row of the symbol.
For 2D matrix symbols, though a more complicated type of barcode, the parameters tested are actually fewer:
1) Unused Error Correction
2) Fixed (Finder) Pattern Damage
3) Grid Non-Uniformity
4) Axial Non-Uniformity
Together, these parameters form the basis for barcode grading, and making sure that your barcodes score highly in each has many advantages. Ultimately, being able to reliably produce high-quality barcodes means that your products will be rejected by suppliers less, saving a huge amount of time and money.
How To Score Highly
Reliably producing good barcodes essentially relies on two things — the quality of your printing, and the frequency with which you assess your barcodes for quality.
First and foremost, if you are frequently failing to produce good-quality barcodes, you need to upgrade your printer, or get it serviced. A high-quality modern printer should be able to consistently produce highly-graded barcodes on a variety of substrates.
Secondly, if you are printing large numbers of barcodes, it is also worth investing in a barcode graded to assess the quality of your codes frequently. This can be a stand-alone unit, but also note that many good-quality printers now incorporate automatic barcode graders into their design.
