List of Substrate Issues to Consider in Prepress Design (1)

Whenever we lifted the substrate, we all thought of paper. However, in fact, the substrate is far more than the paper. This paper mainly introduces the substrate from the perspective of prepress design.

First, paper <br> Wood pulp paper is not as old as we thought. Wood-based papermaking didn't start to flourish until the 1880s. Prior to this, papermaking materials were mainly rags. It is said that humans began to use wood pulp as a raw material for papermaking, which was inspired by the process of wasp nesting with chewed wood pulp. Of course, this is just a legend, there is no exact textual research.

In any case, the vast majority of substrates today are paper materials, and paper materials alone also contain a variety of categories. In the prepress design must fully consider the characteristics of the paper substrate, or even if the designer's creative work is no better, it is also a loss. The following will describe in detail some of the characteristics of paper substrates that prepress designers must consider.

1. Paper sorting The first thing to consider is the most basic paper sorting. Paper is generally classified into bond paper (advanced writing paper), book and paper, glossy paper, coated paper, cover paper, cardboard, ledger paper, newsprint paper, offset paper, onion skin paper, label paper, selenium electrostatic copy paper, and the like. Securities paper (advanced writing paper) is mainly used for printing special stationery and securities. Selenium electrostatic copy paper is the basic paper for printers or copiers, which is what we call “white paper or plain paper”. Of course, different paper mills have different titles. Glossy paper is mostly used for printing on cards or postcards. Newsprint is a kind of wood pulp made of wood, which is cheaper and is mainly used in newspapers. The cover sheet can of course be used to print the cover, and it can also be used to print other wear-resistant prints that require a certain thickness. In fact, the paper industry has developed to today, there are already many paper classifications and related applications. Designers must be practical in practical work.

Consider these issues.
The first step in choosing a job paper is to determine the type of paper used. Obviously, if the print job is a special stationery, it is not necessary to use a cover sheet, because the special letterhead printed with the cover sheet will cause the customer to pay an additional mailing fee due to the increased weight of the mail. But when designing the cover of a paper book, designers will certainly think of using cover paper because it is stronger than other high-thickness papers. But when printing promotional postcards, designers will consider using high-thickness paper, such as glossy paper, because such cards are able to withstand the manual handling equipment of the post office. If the card has not been mailed and broken, the card promotion loses its meaning. If the promotion object receives such a card, the consequences are unimaginable. In fact, the thickness of mailing materials is stipulated by the post office. Therefore, when selecting paper, it is necessary to pay attention to the relevant regulations of the post office.

2. The basic weight of paper Even if it is the same kind of paper, it has the basic weight. The basic weight comes from the thickness of a certain type of paper. For example, the security paper and cover paper that we usually come in have different thicknesses. In general, the paper's basic weight is the weight of a certain level of paper (500 sheets) cut into the basic size and then calculated in pounds, which is the specific calculation of the basic weight. For example, an ordinary 20-pound security paper has a basic size of 17 x 22 inches, which means that 500 pieces of 17 x 22-inch size security paper weigh 20 pounds; 500 pieces of 17 x 22-inch 50-pound security paper weigh 50 pounds. ,And so on.

Although most coloured printing papers dictate the basic use of weight, the cover paper often uses the "points" to measure the thickness of the paper. The "points" here are different from the "points" used in the layout. The number of points used in the paper industry is equivalent to one-thousandth of an inch (0.001), so a 10 point cover paper has a thickness of 0.01 inch; a 20 point cover paper is 0.02 inch, and so on.

Why is the basic paper weight so important? There are many reasons. First, the thickness of the paper affects the print quality and quality of the print. No matter if the selected paper is too thin or too thin, problems will arise when printing. For example, mailing materials need to be bandaged. This requires that the paper used has a certain thickness so as not to appear too thin, nor too thick, or it would have to pay a large postage fee.

When printing marketing materials, product promotion materials, entrainment materials, or image promotional materials, be sure to keep this in mind: If these materials need to be mailed, especially if they are sent overseas, they must use postage economical printing materials. If the customer finds that the paper used has forced him to pay an additional postage, he may not consider you again when he has the same business next time.

The same thing that needs to be considered is the folding of printed matter. The thicker the paper used, the more difficult it is to fold, especially when automated folding equipment is used. This problem cannot be ignored even more. The more difficult it is to fold, the more severe the print will be.

Of course, the designer does not have to remember the basic weight of all the paper, but can always carry the basic weight table. When determining the paper that should be used, refer to the sample provided by the printer or paper mill. This is the best way to determine the problem of paper selection.

3. Surface Finish of Paper When determining the selected paper, you also need to consider the surface finish of the paper. The requirements of the print job on the surface of the paper depend on its end use. According to the surface finish of the paper, it can be divided into high gloss surface paper, matte surface paper, surface coated paper, textured paper, and twilight paper. Among them, the surface-coated paper includes single-side coating (C1S) and double-side coating (C2S). Therefore, when printing special letterhead, it is necessary to consider that the surface finish of the paper should be suitable for writing with a pen, but it is not possible to use some textured surface paper with a high degree of ornamentation, otherwise it would make the signature on the letter paper look like a drunkard. Like that.

In addition, it should be noted that many special letterheads are used for laser printers or other office equipment. These letterheads cannot be too thin or they are not suitable for these office equipments. It is also necessary to consider this issue when printing envelopes too, because many units' envelopes are printed on the printer with the recipient's address name, and these envelopes are also billed through the postage meter. It seems that these problems do not seem to need to be considered, but it is recalled that staff working in the post office often reflect envelopes with very high surface finish (actually those envelopes use synthetic paper, which is lighter than ordinary paper, and the price is very low.) When the postage meter was billed, the ink on the meter was stuck on the envelope. The result was that after the envelopes were piled together, the postage stamp was erased.

An important issue with the paper surface finish is the ink repellency of the paper (its opposite is ink absorption). The ink repellency refers to the extent to which the paper does not absorb (repel) the ink. The degree of concern for this issue depends on the printing method and the printed content. If many of the printed content is a solid color (such as the color of the entire paper is black, etc.), we must consider more of the paper's ink absorption, otherwise it will take a long time for the ink on the paper to dry, and even have It may not be possible to wait for the ink to dry before continuing to the next process.

More seriously, if a job involves glazing, laminating, folding, or other follow-up processes, and these processes are part of the printer's on-line printing, and the ink is not yet dried, the coating adhesion after coating If it fails to meet the design requirements, the printing equipment will stain the printed products when it is running; or the printing jobs have to be forced to take the production line halfway and wait until the ink is air-dried before printing. The cost of doing so would be very high. Not only would the printers require additional fees, but it would also be possible that the duration would approach and no time would be allowed. Even after the ink dried, the printer would not return the job to the production line, which would cause losses. Already unable to make up for it.

On the other hand, paper absorption is too high and there is no benefit. For example, when porous paper is used as the printing paper, the printing color (black is no exception) will appear dim due to the excessive ink absorption of the paper. We know that when an ink jet printer prints on plain paper, the ink will absorb too much onto the paper, and the color on the paper will not be as bright as when printed on a special inkjet paper. People using inkjet printers may have experienced paper creases and wrinkles when printing on damp paper, which is the result of high ink-absorbent papers interacting with high flow inks. Even with traditional printing inks, such problems may arise because different inks have different fluidities.

The results caused by the improper consideration of the ink absorption of the paper not only affect the aesthetics of the printed matter, but also more seriously the problem of the perspective of the ink, that is, the printed text or image penetrates to the other side. This is indeed a very bad thing. For example, during the printing of magazines, advertisements from one manufacturer penetrated into the advertising page of another competitor.

This issue is also related to the ink used by printers. Different presses have different ink requirements. For example, web rotary printing presses, heat setting web printing presses, and small sheet-fed presses, etc., each use different types of inks, mainly different drying methods. So make sure that the paper, design, and ink chosen for the print job are compatible. In addition, the difference between the performance of color inks and spot color inks is also great, so be careful when selecting them.

4.Paper opacity The discussion of the problem of ink repellency and ink absorption has led to the issue of paper opacity. The so-called opacity is the ease of viewing the other side of the paper. When printing jobs such as spot colors, bold lines, or titles on both sides, the paper's opacity should be more stringent.

The above are some of the issues to consider when choosing paper. The use of paper is a very complicated task, not only to consider all the issues mentioned above, but even more. Paper is a very complex printing material. Any of its characteristics does not exist independently of other characteristics. It should be considered comprehensively when studying the characteristics of paper.

For this issue, here is a suggestion to cooperate with the printers when choosing the paper and jointly decide the type of paper to be used. Both parties should solve this problem before the printing job is started to be designed. We often hear from printers complaining that some young “unmanned” designers are unable to print at all, and sometimes there is simply no paper that meets the design requirements. This kind of diaphragm can easily cause serious problems. The consequences, especially when web printing materials are pre-prepared, are even more difficult to imagine. When print quality is bad, the object of complaint is often the printer. But keep in mind that printers are also partners, not competitors. Although the designer's creative mind can come up with any design, the printer is not capable of printing anything.