Barcode printing and its problems

Bar codes often need to be printed on cartons and cartons. This is a printing process that must be required for the circulation of goods. Bar code, also known as line code or simply bar code, is a commonly used product packaging label, can be said to be the identity of the product.
There are two ways to print bar codes: one is the use of printing equipment for batch printing of layouts that are combined with printed graphics and text. The other is controlled by a computer and prints bar code labels and bar code files in due course. The former applies to a large number of barcodes with the same specifications and the same content, and is designed and printed at the same time as the packaging graphic. The latter can be controlled by computers, real-time printing as required, with greater flexibility. Bar code printing devices include inkjet printers, thermal printers, thermal transfer printers, impact dot matrix printers, and laser printers.
In order to ensure that the printed bar code meets the design specifications, the plate making process should be considered according to the printing process and the characteristics of the substrate.
For example, in the flexographic printing process, it is considered that the line width is appropriately reduced in making a plate to compensate for the deviation caused by the distortion in printing. For the printing of heat-shrinkable packaging materials, the position of the barcode after shrinking the film should be considered, and the vertical and horizontal shrinkage factors should be calculated in advance so that the layout can be adjusted according to the shrinkage factor at the time of plate making.
In order to facilitate normal reading during use, attention should be paid to the selection of the printing ink of the bar code. Bar code reading system, set the scanner light source is generally a red light source with a wavelength of 630-700nm, it should consider the red effect of ink.
The scanner's incident light shines on the surface of the bar code of different materials and colors, and the resulting reflection effects are also different.
Black ink can be completely absorbed by red light. The reflectance of incident light on printed materials is generally below 3%. Therefore, most bar codes are designed to use black ink colors for printing. The white ink is totally reflective to red light, and its reflectance to incident light is close to 100%. Therefore, it is the ideal blank color.
For the above reasons, most of the bar codes on printed products are printed directly on white paper. However, some packaging products, from the design and process effects, also have the option to use other colors for printing, so pay attention to match the nature of the color. In general, red, yellow, orange, red, light brown, and the like have high reflectance of red light, while green, black, violet, and cyan have low reflectance to red light.
Reasonably designing the bar code printing color should fully consider the factors such as the reflectivity of the red light. Transparent film packaging is not suitable for direct printing of bar codes. It should be printed with white ink or yellow or orange red as the substrate. Then, dark bar codes, such as black, dark green, and dark blue, should be printed so that they can be easily read and used. .