Application of the hottest hybrid screening and se

Application of hybrid plus and secondary frequency modulation plus technology

ctp is mainly applicable to hybrid plus and secondary frequency modulation plus technology. However, both of them have high-precision characteristics, so there are specific requirements for prepress, plate making and printing process. Otherwise, the final printing effect is difficult to achieve the expected value, and even worse, some aspects are not as good as the quality of traditional 200lpi am plus. Therefore, if users use high-end plus printing, The following matters must be paid attention to in production:

1 Image quality

in terms of quality, it is required that the transition of tone level of the image is normal, the color is saturated and the definition is high. We must avoid using low-resolution images with insufficient information, the loss of tone level and poor quality images with serious merging, abnormal color and definition, etc. Because if there are defects in image quality, mixing plus and secondary frequency modulation plus will not only magnify these defects of the 8-bit continuous tone image when halftoning, but also add the influence of variable factors in the later plate making and printing process, the result of cumulative error will lead to worse print quality

2. Image accuracy

in terms of accuracy, the amount of image information is required to be sufficient, and the resolution of more than 300dpi can ensure the accuracy of printing. The early additive technology requires image resolution = additive factor plus line number, additive factor = 1.5 ~ 2. At present, founder's new additive technology has a unique optimization of the level, so it does not need to be limited to this. 8. In the operation, the formula of adding water while adding material, that is, 300lpi plus does not need to require the image resolution to be 450dpi ~ 600dpi

3. The biggest feature of image type

hybrid plus and secondary frequency modulation plus technology is to highlight the subtle level of the image, that is to say, this point technology is good at giving full play to the fineness, texture and clarity of the image! In terms of image color, the color gamut space of hybrid plus printing is not much different from that of traditional 200dpi printing, and the color gamut space of secondary frequency modulation plus printing is larger than that of traditional 200dpi. However, from the perspective of visual observation and psychological impression evaluation of prints, the performance of secondary frequency modulation plus in color cannot detonate the eyeball of the observer, and the impact is not very obvious, The author guesses that this advantage can only be shown in a narrow range of specific conditions, and hopes to be found in future practice. As for image contrast and appearance, as long as color management is used in CTP printing process, traditional 200lpi can be consistent with hybrid printing

therefore, in order to give full play to the technical characteristics of hybrid plus and secondary frequency modulation plus, the selection of prepress image types in printing production needs to be accurate, that is, not all moving parts can use high-end plus. The precautions are as follows:

(1) generally, images with rich levels of dark tones and uniform distribution of high brightness tones are the best. Such as clothes, leather shoes, wooden doors and other objects with strong texture; The originals with rich high brightness tones and large areas of gentle gradients need to be used with caution, because although the mixing plus and secondary frequency modulation plus can reproduce the complete tone level of these images, due to the influence of late plate making and printing factors, the small dot restoration is not as easy to design as the traditional 200dpi. On the micro level, it shows that some dots are restored well, some dots are reproduced poorly, some dots are full of ink, and some dots are false, Finally, macroscopically, the reflection of prints is that the flat vision is uneven and rough; 10. Install the machine head

(2) the character image (especially the face close-up), which requires high quality of the original image, especially that the step combustion will not produce polluting smoke and dust, and the level transition is smooth, otherwise due to the influence of the original, plate making and printing process, the level transition jump may be caused, and the face is not soft

(3) landscape images (especially the close-up of the sky) also need the original image to have a smooth gradient transition, otherwise due to the influence of the original, plate making and printing process, it may cause the transition jump of the level and heavy sense of particles

(4) for the originals of traditional Chinese painting, oil painting, gouache and watercolor painting, because the general authors paint on rough paper with prominent texture, although the mixing plus and secondary frequency modulation plus point is small, there is a disadvantage of incomplete reduction of plate making and printing points, but it is not a big problem for these originals, and sometimes it even becomes an advantage, so it is relatively ideal to use the mixing plus and secondary frequency modulation plus technology to print such manuscripts

(5) for newspaper printing, hybrid plus and secondary frequency modulation plus technology can be used in CTP printing process. These plus methods will make the image delicate, texture and clarity more prominent, and meet the characteristics and requirements of newspaper printing. Perhaps some users are worried that compared with the traditional newspaper printing, 100 ~ 120dpi am printing will have some faults such as dark tone level merging and blurring, which is understandable. Indeed, this problem exists in the CTF printing process, but in the CTP printing process, the standard of testing machine fixture can be solved through color management

4. Plate making process

hybrid addition and secondary frequency modulation addition technology belong to high-precision addition, and the dots are sensitive to the working state of CTP, so the process control in the publishing process needs to be more strict than ordinary amplitude modulation. If the publication is poor, sometimes there will be stripes, and the uniformity and stability of points fluctuate greatly, so for this kind of hanging, the publishing state needs to strictly regulate the layout design, otherwise the printing will have absolute, texture and rough quality problems

5. The printing process

hybrid addition and secondary frequency modulation addition technology belong to high-precision addition, and the dots are also sensitive to the printing working state, so the process control in the printing process needs to be more strict than ordinary amplitude modulation. If the dot ink in printing is in a good and stable state, such as the virtual and solid color, the smoothness of the edge, the balance of water and ink, the rubber surface and the printing pressure, etc., then the reproducibility and stability of such dot printing can be guaranteed. Otherwise, there will be quality problems such as uneven gradient transition, uneven clothing and large color fluctuation, resulting in the effect of high-end plus printing is not as good as that of traditional amplitude modulation plus printing