It should be noted that the original negatives of printed barcodes must be registered and issued by the International or National Coding Center. The printing process has the following characteristics.
1. Barcode zoom
It is the most common way to directly print barcodes on the printed matter (the magnification is l, which is the original size). It must not be zoomed in or out at random. According to the technical requirements of the EAN organization, the zoom ratio should be controlled within the range of 80% -200%. When the zoom magnification is 100%, the printing pass rate is 97.3%; when the zoom magnification is 90%, the print pass rate is reduced to 95.7%; when the zoom magnification is 85%, the print pass rate is reduced to 25%; When the zoom ratio is less than 80%, the printing pass rate is only 10%. It can be seen from this that with the reduction of the zoom magnification, the printing pass rate is significantly reduced. Therefore, it is better to complete the barcode film providing mechanism when the zoom must be performed.
2. Barcode color matching
The barcode reading system specifies that the scanner light source is generally a red light source with a wavelength of 630-700nm, so the red light effect of the ink color should be considered. The incident light of the scanner is irradiated on the surface of different color barcodes, and different reflections will occur.
Black ink can be completely absorbed (ideal) for red light, and the reflectivity of printed products to incident light is generally below 3%, so black ink is a safe color for barcodes. White ink is completely reflective (ideal) of red light, and the reflectivity of its printed matter to incident light can approach 100%, so it is the safest blank color. However, bar codes are used for packaging. In order to increase the decorativeness, other colors are often used to match the empty space. At this time, it is necessary to pay attention to the red light effect of the color and choose the appropriate combination. Yellow, orange, red and other colors have high reflectance to red light, and green and purple have low reflectance to red light. As long as any color matching that meets the bar code requirements for reflectivity, scanning density, and print contrast PGS value is a reasonable bar code printing color design.