Multiple printing designs for corrugated cartons

In the past, the main function of corrugated boxes was as a transport package, and the surface printing was also very simple. The reason is as follows: First, the carton factory and users do not attach importance to the packaging design of corrugated boxes, and only use the carton as a tool to protect and hold the products. Second, the flatness of corrugated boxes is relatively poor, making it difficult to print exquisite designs; Previous print editions were all hand-printed and could not reproduce the fine lines and dots. Of course, there are also a few printing units and other reasons, which have limited the rapid development of carton printing.

In recent years, with the rapid economic development and increasing exchanges with foreign countries, people are increasingly aware of the importance of packaging and decorating, especially the influx of international supermarkets such as Wal-Mart and Carrefour, and the increasing number of domestic supermarkets. People have changed the traditional shopping habits. At the same time, the sales function of corrugated cartons has become increasingly prominent. Users have increasingly valued the outermost packaging of cartons, the display products and the company's image. At the same time, the universal application of flexographic printing plates (photosensitive resin plates) and the rise of flexographic prepress technology have also given strong support for carton printing.

In the field of packaging design, past color packaging or exquisite packaging designs are mostly achieved through offset printing and gravure printing. Offset printing and gravure printing are mature printing methods. There is still a lot of printability that designers need to pay attention to when designing packaging. Flexo printing is a new printing method. To truly reproduce the designer's packaging design, designers need to Flexography features to learn more. In the prepress design for direct flexo printing of corrugated boxes, designers must pay attention to the following points.

First, a clear expression of the color number of creativity

Daqian world, colorful, especially the designer's eyes, is also good at discovering beautiful colors, and organically organize them together to create a variety of or elegant, or bold, or warm, or have a strong visual impact works. As a packaging design, the ultimate goal is to achieve its own creative results after printing, and to achieve industrial production. Therefore, for the packaging design of corrugated cartons directly flexo printing, in the use of color, we must first understand their own creativity in a few color printing machine to achieve, clear their own ideas through a few colors to express. The number of domestic corrugated cartons flexo printing presses is generally 2, 3, 4, and 6. Before confirming several colors, on the one hand, it is necessary to take into consideration the number of color groups on the printing press, and on the other hand, it must be considered whether the white ink is used or the lacquer is used in the process, so as to finally determine the number of colors that can be used to express the idea.

Of course, under the premise that the same can fully express the design creativity, the number of printing colors should be reduced as much as possible, which is beneficial for the printing operation, quality control, and cost control in mass production.

In addition, there are also many manufacturers who wish to use as many spot colors as possible in order to achieve the uniform color of each batch of products and to play a certain anti-counterfeiting effect. Thus, in addition to the traditional CMYK4 color, its packaging uses spot color inks. However, in actual operation, due to limitations of printing machines, manuscripts that need to be printed on a four-color machine do not show up in any of the four colors at the time of color separation. In the end, they have to communicate with the designer, and the colors are similar to each other. Or make changes to the designer's work.

Because the flexographic printing is transmitted through the anilox roller, the number of the anilox roller determines the amount of ink transferred and the fineness of printing. Normal screen adjustments use high-line anilox rollers to make the dots clear; while field versions use low-number anilox rollers to achieve color saturation. In a color, there are both halftone images, and on the ground, and when they are visually prominent, this color is generally divided into a halftone edition and a field edition separately to facilitate the printing operation. Therefore, when considering the overall color number in the design process, do not ignore this feature of color separation in flexo printing.

In addition, it is often encountered in practice that many corrugated box printers are three-color machines and cannot achieve normal four-color printing. Therefore, in the process of watermarking a corrugated cardboard box, three colors are often used. Reproduce four-color manuscripts. There are two actual situations to consider when producing black with three-color overprint:

(1) ink color cast to produce non-standard black three-color overprint;

(2) Three-color overprinting can make the ink layer too thick, affecting the printing quality and effect.

For the above two cases, the designer needs to understand the condition of the ink when processing the packaging product printed with the tricolor machine. Some printers use the ink color cast to properly consider reducing the color intensity of the selected color. Some articles may not necessarily remove the black version. For example, the reproduction of the food can eliminate the cyan version, and the reproduction of the tree can remove the red version. This maximizes the original style and hierarchy. If the problem of printing color number is taken into consideration at the time of design, the above difficulties will not be encountered before mass production. For example, when we dealt with the design of Tsingtao beer cartons, we took into consideration the fact that we had to implement it through three-color printing presses. Therefore, the watermark color printing process of corrugated cartons was successfully implemented and was promoted in the market.

Second, pay attention to the use of levels

Because of the different tastes of the designers, the characteristics of the products are different. Therefore, there are differences in the style of packaging design. Some of them are pursuing simplicity and some are rich in pursuit. However, if its design works are achieved through flexographic printing, the use of layers in design must attract the attention of designers.

Because the flexible version is a letterpress, the material is highly flexible and deformable, so the dot gain after press is more serious, and in the process of plate making, 1% or 2% of small dots are easily lost during the printing process, during the printing process. The medium can't be reproduced very well. 3% of the outlets will expand to about 10% after printing. It is impossible to achieve a very smooth or gradient effect from 100% to 0%, so the highlights and darkness that the flexo products can express There are relatively few levels in the adjustment area, and the high-yield products with good prints can only reproduce 8% to 10% of the outlets. Therefore, less than 8% of the dots in the design will not show up in actual printing. Such as the use of gradient color, if the network gradient to 0%, in the small network or to have a clear boundary or seal, thus affecting the packaging image. Although each manufacturer has its own way to overcome or solve this problem, flexo printing cannot match offset printing anyway. This feature of flexo is only taken into account when designing to achieve your design after printing.

Another example is the fact that the edges of the image are dimmed, and if they are dimmed to a net, the aforementioned problems will also arise. This requires the designer to consider avoiding the emergence of such problems in the packaging design.

In addition, as mentioned earlier, the number of anilox roller lines used in flexo-ink transfer is different for halftone and field versions. Large areas are connected to local gradients, and printing is very difficult. In particular, the manuscripts with darker colors in the field take care of the part of the mesh tone, and the actual printing on the ground is not true or the color is light; taking care of the field, the halftones are partially stenciled and have dirty spots. Although it can sometimes be solved by selecting an anilox roller with a moderate number of lines and reducing the number of screen lines in the halftone portion, it is in any case inconsistent with the original intention of the designer.

It is worth mentioning that in packaging design, gold and silver ink are often used to enrich the packaging design and improve the packaging quality. When using gold or silver ink, if the pattern contains a halftone, it is better to leave more space in highlights and shadows. The best light spot is better than 20%, because such ink printing dots are easy to paste.

Third, consider printing registration

Like offset printing and gravure printing, flexo printing also involves overprinting problems. In the design of flexo packaging, on the one hand, we must pursue the exquisiteness of the pattern. On the one hand, we must also consider the difficulty of printing. For example, for small texts and designs, to be represented by overprinting, it is difficult to guarantee the accuracy of overprinting, which will inevitably lead to an increase in the rejection rate or unsightliness of printed patterns. Trapping is usually used to solve this problem. Trapping of corrugated boxes is usually 0.5 to 1 mm, sometimes slightly smaller for different printing presses. If under such a big trap, the printing of texts and patterns has difficulty, it must be adjusted accordingly. In particular, the overprinting of complementary colors, the black border will appear at the junction of the two colors, affecting the beauty of packaging. Relatively speaking, dark and light-colored overprints will be much better. In addition, a set of text or color blocks overprinted by multiple units also increases the difficulty of printing. Since most domestically used flexo presses are driven by gears, a deep, light, or two-color regular pattern of color blocks or lines appears in the packaging design, which also causes difficulties in printing.

The embossed pattern on the flexographic plate is formed by brushing off the unexposed portions with a solution of the printing solution and a brush, so the flexographic plate is required for the size of the smallest character and the finest line. For corrugated box printing, we recommend that the finest line should not be less than 0.5mm. If it is an isolated line, it should be appropriately widened. As for the text, the thickness of the stroke is best referred to the above data. Because the stroke structures such as the bold typeface and the Song typeface are different, it is not easy to uniformly set the minimum size. Pay special attention when using the "Dar Song" font because the contrast between the horizontal and vertical lines is too large.

In the use of barcodes, because the flexographic plate is easily deformed in the printing process, the plate material is flatly attached to the circular cylinder and must be deformed. Therefore, attention must be paid to the barcode processing. For different printing machines and different bar code sizes, each bar code must have an amount of reduction beforehand in advance of platemaking to ensure that it can be detected after printing. Of course, this reduction is done by the plate-making manufacturers. Here, the designers should pay attention to the direction and size of the bar code. The bar code size should be based on the standard, and the bar code direction should be consistent with the printing direction.

Fourth, pay attention to the layout of the packaging design effect

In the packaging design, the general designer only pays attention to the finished product effect and flat effect of the packaging, and seldom pays attention to the layout effect of the packaging. Printing is a mass production process. It is necessary to arrange the packaged single figures according to the width of the printing press and the circumference of the printing roller. Therefore, the effect of typesetting must be taken into account in the design. Especially when the individual patterns need to be repeatedly arranged, the colors of the intersecting positions should be the same or the connected pattern designs are continuous, so as to avoid that the partial patterns on a package appear in isolation on the plate due to die-cut deviation after printing. Another packaging that causes the finished product to be unsightly. This type of layout should be avoided as much as possible during design.

The above-mentioned problems involved in typesetting are all small-size packaging. In fact, many of the corrugated-paperboard packaging are large-sized, such as refrigerators, monitors, etc. When designing these large packaging, it is necessary to consider the film output and plate-making dimensions. limitation. At present, the maximum size of the flexographic plate in China cannot exceed 2000mm×1320mm, and the film output is mostly within 1100mm×800mm. When carrying out large-scale packaging designs, the characteristics of these processes must be taken into consideration. Patterns exceeding these sizes are best not designed as a continuous pattern or an overall pattern. Once it is designed in this way, it is necessary to splicing the plates before printing, and then splicing them carefully. After printing, a clear interface will appear on the patterns, which will greatly affect the exquisite degree of packaging. When designing, only considering the convenience of disassembling the large-size packaging printing plate can make the printed product meet the designer's creativity.

V. Try to use vector software when designing

At present, most designers use computers as a tool to present their ideas. The design software is in vector form, such as Illustrator, Freehand, CorelDRAW, etc., in the form of pixels, such as: Photoshop, Panit, etc. Do not all during the design process. Using Photoshop and other pixel-format software, Photoshop is best used to process images or create some special effects. Other lines, text, and color blocks are best created with vector software such as Illustrator, Freehand, and the manuscript is sent to the platemaking company. Platemaking companies can more easily and quickly make some adjustments to the design drafts for the characteristics of flexographic printing, such as trapping, drop curves, etc., to achieve the effect of convenient printing. Designers Deliver Their Design Works as Electronic Data