In the course of business, to make appropriate print quality evaluation is particularly important, the complexity of the process color printing is well known, a print production, often after more than a few steps to complete, involving the company, the staff, etc., in different environments , at different times, also printed or requirements are different evaluation methods. So in this process, the need to set up some norms and appropriate viewing conditions. Therefore, we only environmental restrictions such external factors, in order to print a subjective evaluation, which can be called a fair, objective, in order to reduce environmental impacts due to disputes, so the standard of lighting conditions and the standard light source is a must .
Printed color
Color can be divided into
1, the original color: the reproduction of the original color tone is the purpose of printing and copying, so that the original print and difficult to achieve genuine is the highest standard level of subjective evaluation points.
2, the same batch of color: color refers to the same batch of product error between the same location on the same hue zone of a different sheet.
3, the similarities and differences between batches of color: refers to the color error between different batches of the same product, if each batch of the printed colors are slightly different, when they put together, customers will feel these products are new and old of the points, even doubt it whether inherent quality will be the same as the appearance of instability will cause distrust of goods, naturally give rise to the manufacturer of the printing quality of dissatisfaction.
As a customer and printers want the best value of this color error is zero, but the actual production of the various aspects of the limited conditions, completely eliminate the color error is impossible, only by strengthening the various aspects of quality control, product color quality control in color difference standards. Color tolerance refers to color the customer can accept print proofs with the original or proofing between.
When printing color quality after subjective evaluation is the use of visual method, the observer visually and with the original print or in press proofs contrast, make their own judgment, the main consideration is to what extent quality color prints will be customer acceptance.
Both in the printing process, or the printing quality inspection, the printing operation or quality inspectors should always by virtue of their feelings and experiences, to replicate the fidelity and realism as the standard, the color quality of the printed product to make a comment. Replication fidelity is printed on the document refers to the degree of color tone reproduction. Print is a replica, from prepress to print the entire color reproduction process, the document is based on our work, to reproduce the original color tone is the purpose of a printed copy. Make prints and originals reach doubtful degree is the highest standard of subjective evaluation points.
When no original for comparison, color quality and realism will be printed concerned that it meets the requirements of most people's memory color. Most people have a preconceived object of common habits, if printed in the body color and real objects of different colors, this printed matter can not be referred to as high-quality reproductions. In short, the color quality is a subjective evaluation criteria printed copy real, natural, coordination and, of course, sometimes change slightly with the customer's intent or use of the product. In the past decade, most of the original slides, photographs and hand-painted color version from photography dichroic proofing process, such as to be close to the original color reproduction will be considered valid. The printing places guests Dagao Approved as a criterion, as long as the matter sorted out to 90% in general regarded as qualified.
But the document's definition of today's computers more like guests at a computer screen or printed out satisfactory color proofs see, they think this is the original. Whatever type of originals, they are recorded or appearing color may not be manifested in the general printing conditions, because each system has its own color reproduction gamut limitations. Image capture in the production process are concerned that the original kind, color plate were to be taken to obtain photos as originals places proofing printer with color as the target. Print color quality is the result of an objective assessment of statistical tools to calculate the subjective evaluation, and then converted to its corresponding physical quantities, using as an objective evaluation criteria. This can eliminate the human factor in the impact assessment, the standardization of unified standards of fair evaluation of a variety of printed color quality, and ultimately make it more in line with most people's subjective evaluation criteria. The main objective evaluation method using specific measurement instruments and tools, and a number of standard elements together with the printed image printed measurements. Only by measuring, in a way to automatically control the printing quality possible.