The reason for the unqualified printing quality of books and magazines

One, bar, empty color with improper <br> As the bar code reading is reflected by the reflectance of the light on the bar, the sky, most of the light source of the bar code scanning device is red light, therefore, white empty black The bar code is the easiest to read. In order to reduce the cost of printing, some books and magazines print only one color: red, yellow, or orange, so that the bar code is also printed in red on a white background, yellow on a white background, and orange on a white background. The reflectance on the strip and the space is almost the same, resulting in unreadable; some book cover designers do not understand the principle of reading the barcode, and print black barcodes or print the barcodes on dark blue, dark green, dark brown covers. The place where the cover has graphics and text, the bar code print contrast (pcs value) is very small, so that the scanning instrument can not read. In this case, as long as part of the base color of the cover bar code is hollowed out into white when the plate is made, and the black bar code is printed, the bar code can be read.
In order to ensure the printing quality of the bar code, the color of the bar should be black, dark blue, dark green, brown, and the empty colors should be white, red, yellow, orange. These 16 combinations are the best choices. To understand the absorption and reflection of light, the color of the bar must be able to absorb red light, so that the reflectivity of the bar is low; the empty color must reflect red light, so that the empty reflectance is higher. The maximum reflectance of the bar is not more than 25%, the minimum value of the empty reflectance is not less than 96%, and the barcode printing contrast (pcs value) is 67% to 98%. The bar code scanning apparatus can correctly read the bar code.

Second, arbitrarily scale the bar code size <br> Some books and magazines because of small size (64 open) or too many cover art, there is not enough place to place the bar code, they will arbitrarily reduce the bar code size, resulting in too small or too thin, so that the scanning instrument Unreadable. Therefore, when bar codes need to be reduced, the bar code administrative department must use special equipment to produce the reduced codes, which can only be reduced to 80% of conventional bar codes.

Third, self-produced bar code film <br> Some books and bar code film is lost, they will make a bar code or copy the bar code of the original book, and then take the plate, this practice is not allowed. The quality of the bar code or the photocopied bar code made by oneself is unqualified, and the bar code of the bar code of the plate making and printing is certainly not qualified. Barcodes are lost and must be re-applied to the bar code administrative department to make barcodes.

4. Improper selection of printed paper, ink, and equipment <br> Bar code strips and space gaps are very small. Improper selection of printed paper, ink, and equipment makes it easy to paste the plates during printing. The bars become thick, and the air becomes fine. Width deviation more than ± 30%, the scanning instrument can not read. Therefore, book and bar code printing is best to choose offset printing, paper selection of coated paper, offset paper and other paper with less paper, printing cylinder liner should not be too soft, the ink's fluidity is moderate, to ensure not paste version. Bar code printing should ensure that the bar is clear and the dimensions are accurate, the bar width deviation and the print contrast are within the specified range, so that it can become a bar code printing qualified product.


Wen/Mao Yuanyu