What are the factors that affect the quality of printed matter? 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, some specifications and corresponding observation conditions need to be established.

Therefore, we only limit the environment of this peripheral factors, in order to give a subjective evaluation of the printed matter, this is called fair, objective, in order to reduce the environment caused by the dispute, so the standard lighting environment and standard light source is necessary.

Color difference of printed matter

Color difference can be divided into (1) original color difference: reproducing the color gradation of the original is the purpose of printing reproduction, so that the degree of indistinguishable between the printed matter and the original is the highest standard of subjective evaluation. (2) Same batch color difference: refers to the color error between different prints of the same batch of products at the same position in the same color region. (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.

Both the customer and the printer hope that the value of the color error would better be zero. However, due to the limitations of all aspects in the actual production, it is impossible to completely eliminate the color error. Only by strengthening the quality control of each link can the product's color quality difference be controlled within the specified color difference standard. Color tolerance refers to the difference in color between the printed material acceptable to the customer and the original or draft proof.

Subjective evaluation

When subjectively evaluating the color quality of printed matter, visual inspection method is adopted. The observer makes his own judgment after observing the printed matter and comparing it with the original or printed sample, mainly considering the extent to which the color quality of printed matter can be accepted by customers.

No matter in the process of printing or in the quality inspection after printing, the printing operator or quality inspector should always evaluate the color quality of printed products based on their own feeling and experience and based on the fidelity and sense of reality of reproduction.

Fidelity of reproduction refers to the degree to which a printed copy reproduces the color gradation of the original. Printing is a kind of copy, from pre-press processing to the printing of the entire color reproduction process, the original manuscript is the basis of our work, reproducing the original color tone is the purpose of printing reproduction. The highest standard of subjective evaluation is to make the printed matter and the original manuscript indistinguishable from truth.

When the original is not compared, the color quality of the print is related to the sense of reality, that is, it is required to conform to the most people's memory color. Ordinary people have a preconceived idea of common objects. If the main color in a print is different from the real color, the print cannot be called a high-quality copy. In a word, the subjective evaluation criteria of the color quality of printed matter is to reproduce the real, natural, harmonious, and of course, sometimes with the intention of the customer or the use of the product slightly changed.

Definition of manuscript

In the past, most of the originals came from photographic slides, photographs and hand-painted color drafts. In the process of color separation, it was considered effective color reproduction if it was close to the original manuscript. The printing side of the guest approved manuscript as a standard, as long as can follow 90% generally considered qualified.

But today's computer age manuscript is more defined. For example, when a guest sees a satisfactory color on a computer screen or a printed manuscript, he or she considers it to be an original. Whatever the type of manuscript, the colours recorded or displayed may not be able to be displayed under normal printing conditions, because every colour reproduction system has its gamut limits. In the production process, the material object is the original manuscript for the image ingestion. The color separation plate maker takes the obtained photograph as the original manuscript, and the printer takes the manuscript as the target to follow 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, which is used as the objective evaluation standard. In this way, the influence of human factors in the evaluation can be eliminated, and the color quality of various printed materials can be evaluated fairly by standardized unified standards, finally making them more in line with the subjective evaluation standards of most people. The objective evaluation method mainly USES specific measuring instruments and tools, and measures some standard elements printed with the printed image. Only through measurement can automatic control of print quality be made possible to some extent.

Color quality and production control

In order to produce high-quality color prints, we must strengthen the quality control of the production process, and the quality control mainly depends on the objective evaluation standard of the product, that is, to develop a set of strict data standards, with the help of various instruments to objectively measure and evaluate the color quality of the printed matter 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 printing process, if you can spot check the printed matter at any time, you can find out the problem through the biased data, find out the reason in time, so that the problem can be corrected, so as to ensure the reproduction quality of the printed matter. In addition to using density as a parameter to reflect the color quality of printed matter, it is necessary to promote the CIELab chrominance value of color as a parameter to detect the quality of printed matter.

Every link should be implemented data management, every step must have a detection tool to detect, otherwise there will be a lot of errors. Nowadays, with the continuous progress of technology, color control means in printing have been further developed. The new color management system makes printing color control more convenient and more effective.