Rich black

When printed, solid black is a blend of solid black ink over one or more of the other CMYK colors, resulting in a darker hue than is produced by black ink alone in a printing process. A typical rich black mix might be 100% black and 50% each of the other three inks. Other percentages are used to achieve specific results, for example, 100% black is used with 70% cyan (C), 35% magenta (M), and 40% yellow (Y) to give a “cool” black. “Warm Black” is 35% C, 60% M, 60% Y, and 100% K. Color ink under black ink gives a “richer” result; The additional inks absorb more light, resulting in a closer approximation to true black. While in theory an even richer black can be achieved by using 100% of each of the four inks, in practice the amount of non-black ink added is limited by the humidity of the paper and the amount of ink added during the printing process. (A safe and practical rule of thumb is that ink coverage should not exceed 240% on plain paper. However, papers that “compress” such as . and registration black (or “400% black”) produce very impressive results with laser prints. Rich black is often referred to as “blacker than black. While this is impossible from a color theory standpoint, the difference is often visible on the printed side. The difference is more noticeable in backlit rooms (aka " translite”), where rich black blocks light more completely. Use of rich black should be based on a thorough understanding of printing conditions, including inks, type of print, and most importantly, paper. Use too much ink on poor quality paper, such as newsprint, can literally destroy the paper. Also, too much ink may not dry or complete before the printed result and Get in touch with other pages. The additional ink used to produce deep blacks also results in higher printing costs. Care should be taken when using electronic design programs (for example, when handling a CMYK document in Adobe Illustrator or Corel Draw): “Black” may or may not be 100% K depending on the CMYK profile specified in the settings of the image and Photoshop will render the various shades with RGB values ​​close to black; in an RGB document, black is always equal to the RGB value (0, 0, 0). Another reason to use deep black for small black areas is to avoid trapping problems. Rich black is often used for text printed over a color image or background; otherwise, any slight discrepancy between the printing plates will create a white or colored halo around the text, making it difficult to read.