Printing knowledge

Brochure printing paper notes

  brochure printing paper notes
album print prints a Visual arbitration of goods and works of art, and its quality depends on many factors, paper characteristic is undoubtedly one of the major factors. Excellent paper, able to complete the transfer, make the text clearer, full representation on the paper to obtain satisfactory reproduction. But because of paper and other materials and process technology, the limit, most color continuous tone images are not faithfully copied and reproduced, but only make printing images as close to the original.
, paper properties on printing gloss and effect of
in the process of printing and ink transferred to the surface of the paper, and fill the paper is uneven, the print surface is quite smooth. Printing ink surface specular reflection of the light determines the size of print gloss, and the ink film is closely linked to the characteristics of the paper.
ink film thickness is the main factors influencing the gloss of printed matter. After the maximum paper absorbs ink binders, binders remain in Mexican film in the remaining, it can effectively improve the luster of the printed materials. Ink film thickness, residual binders, the more, the more beneficial to improve the luster of the printed materials. Study: gloss with the increasing trend of ink film thickness, depending on different paper. Figure 1 is printed on the same ink in four different paper prints derived from luster of ink film thickness and curve. Can see from the chart, even though ink are the same, but different paper forms print gloss change ink thickness trends are different. Ink film is thin high gloss coating of paper, print gloss ink film thickness increases, this is due to the ink film masked the original high gloss paper itself, and ink film itself, Sheen was reduced due to paper. As the ink film thickness increases, the paper itself harder through the original high gloss ink film is reflected. When the ink film thickness of 1.5 μ m, paper binders of saturated absorption. Later, with the ink thickness continues to grow, retain more binders, Sheen will also continue to improve. Thin paint cardboard printed in ink gloss ink film thickness increased rapidly, after the ink film thickness increased to 3.8 μ m, sheen is no longer with the ink thickness increases. But no matter what kind of paper, gloss ink film thickness increases the volume should have a limit.
2. paper characteristics
impact on print gloss paper fiber interwoven to form capillary network structure, with a large number of pores, become the basis of absorbing ink. Paper absorption of ink capillary network and binders with solid balance between time determines the print gloss form binders penetration levels. General print gloss enhanced with the absorptive capacity of the paper and reduced.
smoothness and gloss in itself affect print gloss. High smoothness to form uniform smooth ink, thereby increasing print gloss. Gloss paper itself can increase the reflectivity of ink, especially for transparent inks is even more so. Two different kinds of ink printing in 4 gloss of coated paper on results. Can see from the graph, two ink print shiny gloss along with the paper itself increases. Print gloss and gloss between the paper itself than print gloss with stronger correlation between the absorptive capacity of the paper.
can be found from the above discussion, smoothness, shine, and there is also correlation between the absorptive capacity. From the papermaking process is easy to explain that. For example, light treatment improves smoothness and gloss, but also reduce the volume of the pores of the paper, thereby reducing the absorptive capacity of the paper. In addition, surface pH value is printed glossy paper to form an indispensable factor, high pH value, the ink is dry, thus helps to improve the luster of the printed materials.
Second, the effects of paper properties on printing the image tones reproduction
ideal tone reproduction is the most important process for high quality printed images, most bad prints are caused because of tone reproduction problems.
image copy first and foremost requirement is the copied image visually with the original match. But in most cases is impossible. Table 1 lists the different types of paper to copy the image density and density range of the manuscript in 0~2.7 (3.0). Clearly, in most cases, original density greater than the density range of the printed image, and with the decrease of the quality of the paper, can duplicate the smaller the density range, saturation and color, too.
solution is to compress original gradient range so that it matches the density range and paper can reproduce.
third, the effects of paper properties on dot large
1. dot
dot to copy the color change than any other variable. Amount of ink printed on paper will affect the dot, dot printing contrast. At the time of printing in black and white or color *** halftone image, dot will change the screen contrast and cause loss of detail and sharpness of the image. In multicolor printing, the dot gain will result in loss of contrast, image, dark paste, dot died and cause rapid color change.
2. effects of paper properties on dot a lot of
on the smooth surface of the ink on the higher-quality paper produced the best site density, when when the paper quality, ink density on the ground, make a dot, influence the quality of the print.
screen resolutions higher dot diameter small, tiny pits on paper can be misrepresented or omitted small plates dot. Therefore, the line number, the higher the fine prints require higher smoothness. This is a principle of the choice of paper. But in practice, you can adjust ink some of the performance or change the parameters to suit the characteristics of the paper.
four, effects of paper properties on printing precision
for the fine print, registration requires higher tolerances within 0.05mm. In multicolor printing, causing many reasons for misregister, but due to changes in moisture content of the paper and printing process to produce the paper deformation is an important factor.
it is well known that paper moisture lead to expansion or contraction of the paper not only, but due to changes in moisture content change paper size, local, resulting in other forms of deformation, such as curls, folds, etc. Which seriously affect the printing of print workers concerned about the effect of relative humidity on moisture content of the paper.
① must be at room temperature, relative humidity change in high humidity causes moisture humidity relative humidity variations in the rate of change than the rate of change of water content is much larger; when low humidity as well. From this point of view, printing medium humidity conditions most favourable.
II between the lag of a closed loop, this phenomenon is known as the humidity of the paper hysteresis. Performance: a paper water balance under relative humidity conditions, moisture (drying), back to the original in the relative humidity of the ambient air and its moisture content than the original increase (decrease).
to make paper moisture content throughout the paper to keep uniform and commensurate with the printing shop of temperature and humidity; and in order to make the paper decrease in sensitivity to ambient humidity, improving the dimensional stability of paper, prior to printing, to humidity (hanging).

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