Prepress preparation

1.Before preparing for printing, we must first choose the printing method. Because each printing method uses different paper, ink, and printing machine, the process is different, and the printing effect is different, the information to be provided is not the same, and the printing price is not the same. Such as the general advertising page and the company's product introduction select ordinary offset printing (referred to as offset printing), corrugated packaging box can choose offset or screen printing technology (abbreviated silk screen printing), plastic film flexible packaging can choose gravure printing (referred to as gravure) or Flexible printing (referred to as flexo), giant color advertising printing can choose silk screen or large-scale printing, curved surface objects can choose letterpress printing (referred to as embossing), gravure or silk screen and so on.

2. Before the computer is designed and produced, the required manuscripts and artwork (including the company logo and the registered trademark of the product) needed for the production must be prepared. The image should be clear, preferably the reversal film, the photo, and the printer. Printed drafts are used as image originals because of their low resolution and poor scanning performance. Color requirements (mainly non-changeable colors, preferably marked with the value of CMYK). If a page has been designed, it is necessary to provide specific The layout, including the page size, image size, size and color of the text, the size and color of the color patch, the colors referred to here are preferably marked with CMYK values.

3. Design your own page to pay attention to the choice of finished product size. Before deciding on the finished product size, it is necessary to decide how to use a few machines to print, what paper to use (large-sized paper is still positive), and a few pages can be arranged on one sheet. If the sizes are different, if one sheet is not full, then it will be Causes the paper to spread.

4. Before making and exporting, it is also necessary to confirm the number of print colors and whether there is a spot color. General printing is four colors, namely CMYK four colors, printing through this four-color overlay to complete the natural world of various colors. But in some cases, you can add some spot colors, such as gold and silver, to reproduce colors that are not easily represented by four-color overlays. When you use spot colors to reduce the number of printing colors, you can also use spot colors. For example, only red and black pages are available. Two-color, red is generally represented by M+Y, so printing requires three colors, with spot color red printing, two-color printing, can save a department cost.

5. If you have already produced and only need to output, print, the resolution required for each printing process is different, but the required file mode is CMYK, can not use RGB mode output. Ordinary offset printing generally requires output of 133 lpi or more, so the image requirement is more than 260dpi. The low resolution will affect the printing effect; silkscreen generally requires a lower output line number, about 30lpi–60lpi, so the requirement for image resolution is also low. , generally about 100dpi; flexo printing requirements to be selected according to printing materials, general corrugated paper image resolution of 120dpi -150dpi, newsprint 150dpi - 180dpi, coated paper and self-adhesive paper 180dpi - 200dpi, plastic and metal The film is 200dpi–260dpi, and the general dot print is more than 260dpi.

6. When you make your own pages, you also need to pay attention to topics such as bleeding, stamping, and trapping.

In addition, it is also very important to consider the number of copies before printing. The number of prints used by different printing methods is different. (The number of prints refers to the cost of printing, except for the cost of paper. Print this quantity calculation). For example, if the offset number of general offset printing is 3,000 and 5,000 copies, the unit price for printing is relatively high below this number of prints; the number of onsets of silk screen printing is 300, and the printing resistance rate of silk screen is 3,000. The rate refers to the highest number of copies that can be printed on the screen. More than 3,000 copies need to be replaced.