Master these 8 key elements! Unlock the secret to high-quality digital printing
Original processing
Although digital printing gets rid of the plate-making restrictions of traditional offset printing, it has more refined requirements for the pre-processing of the original. The core advantage of digital printing design lies in its efficient and accurate original processing capabilities, which can maximize the restoration and optimization of original design files. During the preparation stage of the manuscript, special attention should be paid to the following key points.
01
Manuscript quality benchmark
It is recommended to give priority to high-precision originals as the basis for digital printing, and their resolution should reach the standard of 300dpi or above. When the quality of the original document is not good, it is necessary to use professional scanning equipment for digital conversion, it is recommended to use a scanner with an optical resolution of 600dpi or more, with the actual output resolution setting of 300dpi, to obtain the ideal printing effect.
02
Color reproduction characteristics
When dealing with special colors in digital printing, it is recommended to retain at least 3% of the dot area in the bright area (highlight part) to avoid disconnection; The dark area (shadow part) should ensure that the maximum dot does not exceed 95% to prevent ink accumulation; For gradient effects, a gradation transition interval of not less than 10% should be set.
03
Special element treatment
For highlighted text, small lines (recommended to be no less than 0.15mm), and small graphic elements, optimization is required. When a design includes spot colors, it should be simulated through the extended color gamut capabilities of digital presses. The manuscript design color filling setting should always be filled in the color of CMYK mode, and do not use special color or RGB color, otherwise it will cause serious color difference.
Select the printing materials
Digital printing has high requirements for the adaptability of printing materials, and it is necessary to comprehensively select paper according to equipment type, printing content and post-processing needs, and pay attention to environmental temperature and humidity control to ensure printing quality and finished product effect.
01
Paper performance requirements
Choose paper with a smooth surface to help the ink adhere evenly, reduce ink spot diffusion and streaks, and improve the quality of digital printing. The digitally printed paper needs to be able to quickly absorb ink, control the diffusion of ink droplets, and ensure bright colors and continuous gradation. Changes in the moisture content of the paper will affect the printing effect, so it is recommended to store and use it in a 30% relative humidity environment.
02
Color and material influence
The whiteness and surface characteristics of the paper will affect the color performance, so it is recommended to choose paper with high whiteness and matching color gamut. Thick paper or special materials should pay attention to the location of the graphics and creases to avoid exceeding the scope of the paper post.
03
Post-processing adaptability
If single-sided lamination is easy to lead to curling during lamination, double-sided lamination is recommended; Before binding, the direction of the paper strands should be considered to avoid cracking at the fold; The polish is prone to cracking at the crease, and the design should avoid complex creases or use high gloss treatment.
Be careful to remove stains (blemishes)
In the practice of digital printing design, due to the imaging principle of digital printing based on droplet deposition technology (inkjet) or electrostatic imaging technology (laser), its color reproduction mechanism is fundamentally different from that of traditional offset printing, and standard four-color digital printing (CMYK) cannot directly present the spot color effect superimposed by percentage dots (except for the indigo 6-color version). Therefore, designers need to use the PANTONE Spot-to-CMYK conversion tool to find theoretical matches for spot colors by comparing the color card database.
Observe the field and overprint
On equipment based on tone reproduction, large areas of field printing are the most prevalent problem. They may be due to changes in the charge on the surface of the paper and the charge itself. To some extent, the electrostatic charge on the surface of the sheet also changes, resulting in streaks and uneven colors on the solid block, which is not the case with the updated system. By using Photoshop or other software to create noise in the field, new presses rarely have this problem compared to older presses.
On the contrary, if you want to get a large area of black field, use a thick black ink composed of yellow, pin, blue and blue ink in different proportions. It is recommended to work with the equipment supplier to find and find the best ink number ratio. Try grading at 60C, 40M, 40Y, 100K or 40C, 20M, 20Y, 100K and use all four colors.
Digital printing can be operated at 400~600dot/in, mimicking tonal dots by generating a grid. Because starting with fewer dots in the original, the grid is limited in size by the chosen shade line and the amount of dots available. If only a limited amount of shadows are obtainable, smooth transitions throughout gradations and blends are difficult.
Observing the Monitor
The color gamut displayed on a monitor is broader than that of digital printing. At the same time, proofing devices, such as inkjet proofers, have a very high resolution, up to 1200 dpi. It is best to create proofs on the machine, then replicate production, and produce color blocks for the printing press to calibrate the colors. Of course, an advanced and high-end color management system is also a good solution. Currently, some vendors are able to provide such advanced color management systems.
Choosing the Right Software
Software like QuarkXPress, Adobe InDesign, Photoshop, FreeHand, and Illustrator each differ slightly in terms of color. If the same color is used to create images in Illustrator, FreeHand, and Photoshop, and then imported into PageMaker or QuarkXPress, converting all files to the CMYK color space will result in mismatched colors in those three programs. The colors need to be adjusted to achieve the corresponding color balance.
Collecting Products
Make sure the product includes all fonts and linked graphic files (do not embed graphics via copy and paste). Save files in the appropriate format; PDF/X-4 or TIFF is often recommended as the final output format for printing services to reduce color differences in printing.
Proceed with Post-Processing Immediately
Digital printing products may encounter some issues during binding, such as paper curling or rough paper texture. Varnish is different from ink, as it sits on the surface of the paper and is not absorbed. When folding, the varnish can easily crack along the crease, so avoid printing designs on crease areas, or use higher gloss or reduce paper grain in the crease area to minimize cracking. If the printed material is a book, registration is an issue when printing on a single sheet. The image and text areas should not extend beyond the imposition marks, especially to avoid printing over the marks, and overly tight registration should be avoided, allowing for up to 1/8 inch variation.
For thick paper, ensure that images and text are within the imposition marks and do not exceed them to reduce cracking of both paper and varnish. High-performance printing presses can handle these potential issues. If your product requires very fine results, carefully choose the digital press and thoroughly check sample prints produced by the machine.