The QR code can be monochrome black or multi-color superimposed. The main factors affecting the quality of QR code printing are color contrast and overprinting errors.
1. Color contrast
Insufficient color contrast of the newspaper QR code will affect the recognition of the QR code by the mobile phone software. Optical characteristics requirements of barcode printing symbols: In order to read reliably, after printing, the lines and spaces in the barcode should have obvious contrast, the reflectivity of the spaces should be as large as possible, and the reflectivity of the lines should be as small as possible. According to the national standard, the whiteness of domestic newsprint is more than 50%, and normal printing can meet the identification requirements of QR code. However, it should be noted that when making a QR code on a newspaper, the editor should be reminded not to add shading to prevent the situation where the contrast is not enough to affect the reading.
2. Overprinting error
Mainly refers to the color QR code. The QR code must be neat and clear when printing. Generally, we stipulate that the maximum value of the overprint error (overprint error between the main color and the picture) should be less than or equal to 0.4 times the nominal width of the narrowest line barcode.
According to the national standard, the overprinting error of newspapers is required to be less than or equal to 0.3mm. In fact, some newspapers at or above the provincial level with more advanced printing equipment and higher quality requirements can fully meet the standards in this regard. For some local and city newspapers, if the overprinting is not stable, it is recommended that the QR code be printed in one color, so that there is no overprinting problem.
Printing missing some elements
When printing, be careful not to lose elements on the printing plate, so as not to cause difficulty in reading the QR code. In printing, due to the printing plate or blanket, it is easy to cause the defect of the printed pattern. For the slightly “fragmented” pattern of the two-dimensional code, special attention should be paid to the pre-press and post-check.
Printing ink problem
To control the size error of the two-dimensional code symbol, the key is to control the ink color and printing pressure during printing to ensure the accurate restoration of the two-dimensional code stripes. Under normal conditions, we need to ensure that the ink is “small in water and small in ink”, and at the same time ensure the necessary thickness of the ink layer. There is no false streak caused by low pressure or insufficient ink color; no streak diffusion caused by excessive pressure or large ink.
Post time: Aug-16-2022