Reassess CTP (II)

Recently, a 1 bit TIFF that is closer to the final output form has emerged as an intermediate data workflow. Although the openness of the format and the assurance of output have been recognized, due to the large data size and difficulty in correction, it is usually not standardized. Intermediate data, but since Drupa 2000, various machines that use 1bitTIFF as the input and output have been introduced one after another. One of its advantages is that its output is guaranteed to be high, and it will take time for the PDF to ensure accurate output. On the other hand, regarding the work flow of 1 bit TIFF as intermediate data, according to the original procedure, only quality is guaranteed in the prepress project, and then printing and printing can be assuredly output. Therefore, we noticed that 1bitTIFF, especially for large-scale printing companies specialized in advancement, could not need to be eager to carry out organizational and operational integration and enjoy the benefits brought about by CTP; the second reason is that: Practical high high compression. So far it has been resolved as a difficult data specification issue, and applications such as page numbering, confirmation, correction, CIP3, register adjustment, and tune adjustment have been developed one after another, accelerating the development of this trend.
For example, there are three file formats that are currently considered as intermediate formats of CTP: one is a genuine PDF, the other is a CEPS PDF, and the third is a 1 bit TIFF. Each has its own advantages and disadvantages, and it is necessary to use it for purpose.
The trend of proofing
One of the important factors that make up the CTP technology is proofing. How to make a sample at the time of CTP production is very important for productivity, cost and quality.
The proofing was originally done on the platform proofing machine, but since the digitalization of the prepress project with DTP, due to its high stability, the demand for direct digital color proofing (DDCP) has been increasing, and it is possible to confirm the moiré and text lines. The dot output; Under the lighting source, if you want to achieve the same effect as the formal printing, you should use the same pigment as the official printing ink in the coloring material, and ensure that the paper output to the official printing is already Used. At present, DDCP has a variety of methods, using materials with different characteristics, and using them according to the work flow, the use of proofing and the type of printed matter.
From the aspect of the use of proofing, it can be broadly divided into two types: external school use and internal school use. External school is for the customer to confirm the use of hue, tone, layout design, text, outlets and other requirements as close as possible to the final print, usually using laser thin film thermal transfer. Type of DDCP. However, due to the high unit price of such proofs and proofs, it is more cost-effective to use the CTP version of the official printing press when multiple sheets are required. The internal school is used to confirm the results of operations within the factory and in the production process. In the prepress process to confirm the color or tone of the image produced by the scanner, a method such as laser silver salt photography, which is relatively inexpensive and has a high output speed, is used. In addition, the ink-jet DDCP is not only inexpensive, but also can accurately determine the text, paving, and layout, etc., for inspections of page numbers and layouts.
According to the Color Management System proposed by the International Color Consortium (ICC), it is easy to produce a DDCP that conforms to the final printed product. Originally, the four-color space was first converted to three-color space, and then reverted to the four-color space. At this time, there was a decrease in color information, resulting in a problem of large changes in ink characteristics and UCR amount, but recently, energy has been developed. A color management system that maintains the ink characteristics and is put into practical use. According to the progress of this color management system technology, the performance of the inexpensive and easy-to-use DDCP itself has been improved. Even a simple DDCP can faithfully reproduce the color printed on the official press.
The goal of the color management system project is to solve the problem of color reproduction instability of the DDCP target value (ie, the final printed matter). There are many variables in printing such as paper, ink, water, blankets, and temperature and humidity. Even if the printing presses in the same workshop are subject to different changes, there are also changes in the same printing press.
In addition, for prints that are less important for color reproduction such as advertisements or reprints, the use of simple DDCP and the receipt of data in the form of a color-printed copy, the quality is handed to the printing company, and it is distributed to the printing company. The absence of proof printing for remote proofing and proof printing without printing is increasing. It is important to improve the stability of each printing press. If the shop floor is considered, the standardization of printing conditions is indispensable. . (To be continued)