- Mar 14, 2018 -
In the process of business transactions, to make the appropriate print quality evaluation is particularly important, the complexity of color printing technology it is well known that a print production, often after a dozen steps to complete, which involves the company, staff, etc., different environment, different time, also for print or require different evaluation way. So in this process, we need to set some specifications and corresponding observation conditions.
Therefore, we only have restricted the periphery environment factors, to print, the evaluation is subjective, it is truly fair and objective, to reduce the row caused by environment, so the lighting environment and standard light source is a must.
The color difference of printed matter.
The color difference can be divided into (1) the original color difference: the reproduction of the original color order is the purpose of printing reproduction, so that the degree to which the printed matter and the original manuscript reaches the true and false difficulty is the highest standard of subjective evaluation. (2) the same batch color difference: it refers to the color error between the same batch of products in the same hue area and different printing plates. (3) the similarities and differences of color: refer to the same color error between different batch of products, if each batch of printing color slightly different, when they put together, will feel these goods with old and new customers, the inner quality of even doubt it will like appearance is not stable, will cause mistrust of the commodity, nature will cause dissatisfaction with the manufacturers of printing products quality.
As a customer and printer all want the best value of the color error is zero, but due to the limitation of various conditions in practical production, it is impossible to completely eliminate the color error, only by strengthening quality control of each link, make the color of the product quality control within the prescribed standards for color difference. The color tolerance refers to the color difference between the printed matter and the original manuscript or the manuscript.
For subjective evaluation of color print quality is using visual method and visual observer print and compared with original or printed version sample, to make their own judgments, main consideration is the color print quality to what extent will only be accepted by the customer.
No matter in the printing process, or check the quality after printing, printing operators or quality inspectors shall, from time to time, with his feeling and experience, on the basis of replication fidelity and realistic, with the quality of the color printing products.
The fidelity of reproduction refers to the degree of reproduction of the color order of the manuscript. Print is a kind of reproduction. The original manuscript is the basis of our work, and the color order of the original manuscript is the purpose of printing reproduction. It is the highest standard of subjective evaluation to make the printed matter and the original manuscript to the degree of authenticity.
When the manuscript is not compared, the color quality of the printed matter is related to the sense of reality, which requires it to conform to the memory color of most people. Generally, people have the habit of preoccupation with common objects. If the main color of the printed material is different from the real object, this print cannot be called a high-quality reproduction. In a word, the color quality subjective evaluation criterion of printed matter is to copy real, natural and coordinated, and of course, sometimes it will change with the customer's intention or product's use.
Definition of manuscript
In the past, most of the original manuscripts came from photographic slides, photographs and hand-painted color drafts, which, in the process of color separation, were deemed as effective color reproduction if they were close to the original manuscript. In the printing aspect, as the guideline of the guest approval, as long as it can be followed up to 90% as qualified.
But there are more definitions of the original version of the computer age, such as the customer's satisfaction with the computer screen or printout of the manuscript, which they consider to be the original manuscript. No matter the original draft of any type, the color that they record or appear may not appear in the general printing condition, because each color copy system has its color domain limitation. In the process of production, the image ingestion is the original manuscript, which is the original manuscript by the chromatographer, and the printer USES the manuscript as the target of the color.
Objective to evaluate
The objective evaluation of color quality of printed matter is to calculate the result of subjective evaluation by statistical means, and then convert it into corresponding physical quantity to be used as objective evaluation standard. This can eliminate the influence of human factors in the evaluation, and the standardized unified standard will evaluate the color quality of all kinds of printed materials and finally make it more consistent with the subjective evaluation standard of most people. The objective evaluation method mainly adopts the special measuring instrument and tool, and carries on the measurement to the standard elements printed out with the print image. Only through measurement can the automatic control of printing quality become possible to some extent.
Color quality and production control.
In order to produce high quality color print, must strengthen the quality control of production process, and quality control mainly depends on the objective evaluation standard of the product, develop a rigorous specifications, materials with the aid of all kinds of instruments to objectively measure and evaluate the color of the print quality and other aspects of the quality.
The purpose of color control management is to improve the small gap between manuscript, sample and product. In the process of printing, if you can spot check at any time to print, you can found the problem by the biased data, timely find out the reasons, to correct the problem, so as to ensure the quality of the print copy. In addition to using density as a parameter to reflect the color quality of printed matter, it is necessary to promote the color CIELab color value as the parameter to detect the quality of printed products.
Every link should be managed with data management, every step must have the detection tool to detect, otherwise there will be a lot of mistakes. Nowadays, with the continuous advancement of technology, the color control method in printing has been further developed, and the new color management system makes printing color control more convenient and more effective.