Whiteness of paper

The printing staff always pays attention to some new ways to achieve value-added for the customer's products, but it will not increase the expenses. One of the most effective ways is to become a customer's source of information. By answering customer questions, let them understand the printing process and help them find more effective ways to make their jobs better, so that they can be unique in the industry.

During the printing process, designers often feel that the headache is choosing the right paper for each job. They may want to know what kind of paper is best for copying vivid pictures, how the used paper affects the quality of the image, or what recent improvements in the context and cover paper can be used for their design. If printers can provide customers with the information they need, they can help them create high-impact work, increase their satisfaction, and gain their trust in the process.

It is not easy for printers to answer these questions. So understanding the characteristics of paper can help us explain to customers, ensure a smooth printing process, and increase our interest.

First, let's look at the whiteness of non-coated offset paper. It sounds like it is simple, but there are many features that affect its performance. Weight, texture, finishing and coloring are the most prominent factors, but other smaller details are also critical factors. Whiteness is the most critical factor.

It can affect the processing of the paper on the press and the effect after the job is completed. This may have two different effects. One is to satisfy the customer. The other is to push the customer to the competitor.

In order to make better use of the whiteness level, we should have a clear understanding of the level of whiteness of the paper and how the paper achieves different levels of whiteness.

The whiteness level is how the measured whiteness actually refers to the amount of light reflected from the surface of the paper, which can be represented by the result of comparing the amount of light reflected from the surface of the paper with the amount of light reflected from the standard surface. These two tests form a ratio, like the brightness value from 90-100. The higher the ratio, the higher the whiteness level.

Whiteness is a factor that distinguishes paper grades. Now, printers often require non-recycled paper to have a whiteness of at least 90. (The whiteness level of recycled paper may be lower, but it is usually 92.) People feel good about high whiteness products and make the products have value-added effects. The industry standard requirement for Number 1 Opaque is 92; Premium Number 1 has a whiteness range of 94-98.

How whiteness is achieved thanks to advances in technology, manufacturers have been raising the brightness level of their paper. Since the 1970s, there have been significant improvements in the bleaching process of pulp fibers, resulting in a whiter fiber. Manufacturers have also developed optical brighteners to absorb UV light and convert them into visible light to re-disperse - very similar to the bluing agent used in dry cleaners.

Modified paper fillers can also be used to improve whiteness. As a result of technological improvements, manufacturers have been able to use calcium carbonate as fillers to develop whiter paper at a reasonable cost. Many manufacturers have built their own calcium carbonate production plants so that they can customize different sized particles to optimize paper density and opacity.

How paper brightness affects design and production effectiveness The improved whiteness level has a strong impact on paper performance, which is good news for printers and their customers. When the printer understands that the design elements have a higher degree of whiteness, they can turn the better-quality jobs printed into high-quality jobs.

For black-and-white jobs, paper with a higher degree of whiteness provides better contrast, which is helpful for the clarity of photos and graphics. For color jobs, paper whiteness can increase color saturation. Because the ink is not completely transparent, light penetrates the ink particles and reaches the underlying paper surface. When more light is reflected, the effect of color expression will be more fresh and bright.

When using different grades of paper to print jobs again, it is also wise to consider paper whiteness. If the whiteness of the paper used for reprinting is not as high, then the effect of color reproduction will be affected. We may need to change the ink to get the same exact copy effect. When we compare the printed sample with the original, it is best to observe under a standard light source, because different light sources reflect in different ways.

More filler content also requires the printer to perform special operations on them. Papers with greater whiteness often have higher filler content. These fillers include the calcium carbonate component, which is slightly soluble in acidic water tank solvents. When these fillers begin to dissolve, they appear on the printing press and whiten the blanket. Therefore, the printer asked to ensure that their fountain solution and ink were formulated for alkaline paper.