Notes on design and production of Cigarette Drawer Box Packaging before two-color printing

Notes on design and production of Cigarette Drawer Box Packaging before two-color printing

Two-color printing brush design, simply speaking, refers to a certain image through the color processing technology, the use of two different color ink combination, reproduce the original effect of the business card printing process. In general, C, M, Y, K four-color printing plates, black (K) plate and other three-color (C, M, Y) printing plates any combination, because the black plate in the dark tone of the image level information distribution is strong, can enhance the contrast of the image tone. In the bright tone, the black tone information is weakened, and the color layers of C, M and Y are stronger. In this way, the layer changes of the image can be superimposed with the color changes, and it is easier to reproduce the original color layers and tone information of the image. The combination of C, M and Y, although the color range is large in the bright tone, but the lack of image layer in the dark tone, resulting in the image tonal contrast is small, difficult to reproduce the original effect of the image. Therefore, two-color printing design mostly refers to the combination of black and other spot colors.

The key of two-color printing design is to achieve the desired color effect by changing the relationship of two-color combination on the basis of fully protecting the original level and tone information of the image, and the best tool to achieve this color effect is the two-tone in Photoshop image processing software. Two-tone is to adjust the curve of two different colors to achieve the image desired by the graphic designer. In other words, two-color printing design is not a direct reduction of C, M, Y and K (two channels are subtracted and two channels are retained), but based on the structure principle of grayscale image itself. Use the Curve tool to adjust the two colors and recombine the colors at different levels.

The right way is to:

1. Ensure that the original image is in RGB mode. It is not CMYK mode (Because RGB mode is a color mode based on optical principles, and CMYK mode is determined by the absorption characteristics of paper ink, so RGB mode has a larger color range than CMYK mode. RGB mode can represent many colors, especially vivid and bright colors. That is to say. Compared with CMYK mode, RGB mode can reflect richer information of image hierarchy and tone.

2. Then change the RGB mode to Lab mode, delete the two color channels a and b, and keep only the L brightness channel. Then, the L luminance channel mode is changed to Grayscale grayscale mode (Because Lab mode has good characteristics, it contains the widest range of colors, making up for the shortcomings of RGB and CMYK color modes. That is to say, the gray mode transformed by Lab mode can retain the step information of the original image more comprehensively than the gray mode directly transformed by RGB and CMYK).

3. Use the two-tone tool for double g1lh2jg color design of the gray mode image. In the process of using the two-tone tool, you can achieve the ideal two-color effect by adjusting the two-color curve according to your own design needs. The two-color design is then stored as a PhotoshopEPS file. In this way, the color separation task of the two-color printing design image is completed, because the two-color printing design technique lies in the two-color design of the image.

There are some graphic designers due to a lack of understanding of the principles of printing technology and the performance of Photoshop software is not proficient. Therefore, the wrong method is often used for two-color print design. There are mainly two forms as follows:

One is to directly select the image components of the two corresponding channels in the four color channels C, M, Y and K, or select the two channels with rich image levels to output plate making. This method only uses the local level information of the image at the expense of the level information of other channels, which will inevitably lead to image distortion.

Second, in order to enhance the step information of some channels, the CMYK mode of the image is first transformed into Grayscale grayscale mode, that is, the four-color channel is merged into a monochrome channel, and then back to the CMYK four-color mode. Finally, the image components of two corresponding channels are selected to output plate making. Compared with method 1, although the level of images in some channels is improved, the level information of other channels is still lost more, resulting in image distortion.

The basic elements of layout design are composed of images, vector text, decorative lines and color blocks, which requires that the two-color design image must be combined with its corresponding captions, and the color of the text, decorative lines and color blocks in the group software is defined by its own palette, so the key to two-color printing design skills is:

Two-color Photoshop images imported in group software (such as Pagemaker, Freehand, etc.) must be used as two-color Photoshop images in group software. For example: An image designed with Photoshop's two-tone tool has spot colors black and PANTONE1915. When this image is put into Pagemaker, Pagemaker's color palette automatically brings the two spot colors black and PANTONE1915 into the image. When defining text, thread, and block colors in Pagemaker, only two spot colors, black and PANTONE1915, must be used to ensure that the book's late output plate is two-color.