Barcode introduction and printing overview

The bar code has a one-dimensional bar code and a two-dimensional bar code. Bar code code system more, such as one-dimensional bar code UPC code, EAN code, 39 code, ISBN code. The two-dimensional bar code is developed for the shortcomings of one-dimensional bar code information with small capacity and the ability to reduce the bar code area and improve resistance to pollution. It differs from the one-dimensional bar code in that text data can also be bar coded, and its data can be applied not only In English, numbers, Chinese characters, symbols, fonts and even blanks can also be handled, information storage up to 1100 numbers (one-dimensional bar code only 15 numbers). In addition, two-dimensional bar code can also use encryption technology to greatly improve the anti-counterfeiting performance of goods.

In addition to regular barcodes, there are some new types of barcodes, such as:

(1) Invisible bar code. Stealth barcodes mainly include cover-type invisible bar codes, photochemically processed invisible bar codes, and invisible ink-printed invisible bar codes.

(2) Watermark magnetic code. The watermark magnetic code is a binary interval created by the computer after the wet magnetic coating is produced. It is retained in the magnetic oxide after drying, resulting in a unique unchangeable 12-digit number, plus a special magnetic head. Watermark magnetic verification track for reading. The watermark magnetic code can be combined with a hologram to form a holographic magnetic strip anti-counterfeiting technology, so as to form a better anti-counterfeiting effect.

(3) Metal barcodes. Compared with ordinary bar code, it has the features of no fear of stains, strong anti-aging ability, and can also be made into invisible bar code. There are also new two-dimensional metal bar codes.

Barcodes can be printed in various ways such as offset printing, letterpress printing, gravure printing, screen printing, and non-printing (ink-jet printing). No matter which method is used for printing, the printing quality is required to be good. To sum up, there are mainly the following aspects:

(1) In order to ensure correct scanning and reading, the printed bar code shall be neat and legible, and the symbol shall be indistinguishable (defective point). The blank symbol shall have no residual black spots (blotches). Usually the maximum diameter of the flaws and stains shall be ≤ the narrowest bar code. 0.4 times the nominal.

(2) Controlling the size error of the barcode is to improve the read-first rate of the reading device and reduce the decoding error rate. This will not only improve the quality requirements for plate making, printing or printing, but also increase the tolerance requirements for reading devices.

(3) In order to read reliably, the bars and spaces in the bar code after printing should have obvious contrast signals. The larger the contrast signal of the bar code, the better the reading performance.

(4) Printing tolerance must be strictly controlled when printing, otherwise it will affect the reading effect.

(5) There is a certain requirement for the edge roughness of the barcode. When the roughness is too large, it cannot be read.

(6) The bar thickness and the empty ink layer thickness should generally be controlled within 0.1mm. Otherwise, the correctness of the reading will be affected by the different scanning planes between bars and spaces.

Reprinted from: Ke Yin Media