Why is there a difference in color after using CTP?

Why is there a difference in color after using CTP?

Customer: "Hello, hello!"

　　 Engineer: "Hello!"

　　Customer: "Are you Chen Gong?"

　　 Engineer: "Yes, what can I do for you?"

　　Customer: "Why use CTP, the color is still different, isn't it that CTP is easy to use"

　　…………

　　 The above is a telephone conversation between the customer and the engineer.

　　 Why is there a difference in color after using CTP? Now, let’s analyze the customer’s misunderstandings. The first is that customers have two major misunderstandings: the concept confusion between plate making and printing plate output, and the confusion between color management and color correction.

　　 If you can't know the above four concepts highly, you will step into an inextricable abyss and bring you infinite distress from then on...

What is plate making?

　　 Plate making is a general term for copying manuscripts into printing plates.

The basic requirement of plate making is to be faithful to the original manuscript. If the designer is making the draft, when the color reproduction is biased, the color is required to be corrected. That is why, the clothing picture album or the art picture album must be repeated 2-4 times. The reason, or there will be more...

What is printing plate output?

The printing plate output is the electronic document page submitted by the customer by the printing plate output center, and the printing plate is output after being assembled into a large plate according to the printing and binding requirements. The basic requirement is to be faithful to the document page, according to the printing plate output compatibility and the scope of printing technology. Keep as much of what you see on the page as possible. This is what you see as the difference between professional graphic production software and office software, and the difference between printed PDF and certified PDF.

What is color management?

　　The color matching problem is caused by the different color spaces used by different devices and software. One solution is to use a system that can accurately interpret and convert colors between devices. The color management system (CMS) compares the color space of the created color with the color space of the output color and makes necessary adjustments to make the colors displayed by different devices as consistent as possible.

　　 The color management system converts colors with the help of color profiles. The profile is a mathematical description of the color space of the device.

What is color correction?

　　 Since the printing plate output is faithful to the document, that is, the original color value output is the color of the color value, so the color of printed matter or digital proofing cannot meet the needs of customers, which requires color correction during front-end production.

　　 Don't confuse color management with color correction. The color management system does not correct images that have hue and color balance issues during storage. It provides an environment in which images can be reliably evaluated based on the final output.

Understand the above concepts, then you can no longer do useless work, like the same single job, previously used film plate printing, now it uses CTP plate printing. The colors of CTP live parts are in the dark and bright parts and the film printing. The big difference is that the CTP outlets can reach 1-99%, while the outlets below 3% of the film are more difficult to expose.

　　 Regarding the color inaccuracy, you cannot always adjust the printing plate curve and digital proofing curve to adapt to the individual printed product color. You should master the quality control of the printing press as soon as possible.

The color printed on the CTP version is inaccurate. There are also the following reasons. Since the printer master has just started using the CTP version, he is not fully familiar with the details of the CTP version, and there are factors of piece counting. The ink is no longer adjusted, and some are the color matching of the printed product and the original film sample, and the color of the printed product and the quick-print sample. The customer is instructing the color correction. If it’s a customer doing color correction on-site in the printing workshop, it’s really useless. Each customer’s standards are different, and color mixing on the printing machine can only be achieved by increasing or reducing ink. For pre-press plate making , It is difficult to know how many dots can print what kind of color.