Bar code to make bar code to be able to be correctly identified by bar code recognition, bar code lines straight, not broken lines, line edge to smooth and sharp, no saw teeth, line distance meets the standard, line blackness to foot, the contrast to large. The technical requirements of bar code are mainly:
1. size zoom. Bar code is usually the original large direct printing, and to enlarge or reduce the printing to the technical requirements of the EAN organization, can not be carried out at will, generally stipulates that the scaling rate should be controlled from 80% to 200%. The scaling rate of bar code has a great influence on the pass rate of printing. Therefore, it is better for the scale printing to be completed by the bar code film supplier.
2. color matching. Because the bar code recognition system stipulates that the general scanner source is a red light source with a wavelength of 630nm to 700nm, the red light effect of the ink color should be considered. The incident light of the scanner irradiated on the surface of different color barcodes will produce different effects of reflection. Black ink can fully absorb red light. The reflectivity of the printed matter to the incident light is less than 3%. It is the most safe and ideal bar code color. The white ink will reflect the red light completely. The print to the incident light is close to 100%, it is the safest blank color, so the bar code is usually printed in black and white monochrome.
3. the requirements for the seal. In terms of optical properties, in order to ensure that the scanning light source has a 45 degree angle incidence and 15 degree reflection, the substrate is required to have good light dispersion characteristics. In terms of materials, paper substrates are generally white on the white surface of the paper itself, and have certain requirements for whiteness, opacity and gloss of paper.