Print quality refers to the comprehensive effect of various appearance characteristics of printed matter. From the perspective of reproduction technology, printing quality should be based on the "faithful reproduction of the original" as the standard. Whether in the traditional printing process or in the digital process, the printing should be faithful to the original copy.

Printing quality control elements

For printed matter, there are four control elements: color, level, clarity and consistency.

1. Color is the basis of product quality, which directly determines the quality of products. Color control or management is always a key link in the research and analysis of printing professionals.

2. Level is the gradient, which refers to the change of color gradient that can be recognized in the image. It is the basis of accurate color reproduction.

3. Definition refers to the clarity of image details, including three aspects: the clarity of image fine level, the clarity of image contour edge and the clarity of image details.

4. Consistency consistency is uniformity, which includes two aspects. On the one hand, it refers to the consistency of ink volume in different parts of the same batch of printed matter, that is, different ink areas. Generally, it is measured by the consistency of vertical and horizontal field density of printed matter, which reflects the stability of different parts of printed matter printed at the same time. On the other hand, it refers to the consistency of the density of different batches of printed matter in the same part, which reflects the stability of the printing press. On the other hand, it refers to the consistency of the density of different batches of printed matter in the same part, which reflects the stability of the printing press.

For printed matter, as long as these four aspects are well controlled, namely the color, level, clarity and consistency of printed matter can be well controlled, high-quality printed matter can be obtained.

Printing quality control method

One of the methods of printing quality control is to use the conventional signal bar, test bar, control bar and ladder ruler to control the printing quality (including printing quality and printing engineering quality) scientifically and quantitatively. At present, there are many kinds of signal bars and test strips used in various countries, such as GATF system in the United States, Bruner system in Switzerland, vergera system in Germany, and Glinda system. The signal and test strips of GATF and Brunner are mostly used in China.

The commonly used detection tools include signal bar, test bar, control bar and ladder ruler. The signal bar is mainly used for visual evaluation, with single function, and can only express the appearance quality information of printed matter. Such as sun degree ladder ruler, GATF code signal bar, color signal bar, etc. The test strip is a multi-functional marker element based on densitometer detection and evaluation. It combines visual identification with densitometer test, and carries out numerical calculation with charts and curves. Control strip is a multi-functional control tool which combines visual evaluation and test evaluation of signal bar and test strip. For example, Brunel's third generation control article. A ladder ruler with equal difference density or dot, used to control the quality of printing and printing.