Rich black

Last updated

Rich black, in printing, is an ink mixture of solid black over one or more of the other CMYK colors, [1] resulting in a darker tone than black ink alone generates in a printing process. [2] [3]

Rich black
#000000
Gtk-dialog-info.svg    Color coordinates
Hex triplet #000000
sRGB (0, 0, 0)
HSV (0°, 0%, 0%)
CIELChuv (0, 0, 0°)
CMYK H[ failed verification ]
Rich black (typical)(60, 40, 40, 100)
Cool black(70, 35, 40, 100)
Warm black(35, 60, 60, 100)
Registration black(100, 100, 100, 100)
SourceHodges [1]
H: Normalized to [0–100] (hundred)

A typical rich black mixture might be 100% black, 50% of each of the other three inks. Other percentages are used to achieve specific results, for example 100% black with 70% cyan (C), 35% magenta (M), and 40% yellow (Y) is used to achieve "cool" black. "Warm Black" is 35%C, 60%M, 60%Y, and 100%K. The colored ink under the black ink makes a "richer" result; the additional inks absorb more light, resulting in a closer approximation of true black. While, in theory, an even richer black can be made by using 100% of each of the four inks, in practice, the amount of non-black ink added is limited by the wetness that the paper and printing process can handle. [4] (A safe and practical rule of thumb is that ink coverage should not exceed 240% on normal papers. Papers that "pick", such as low-end recycled papers, should have even less coverage.) Wetness is not a problem with laser printers, however, and registration black (or "400% black") produces very striking results in laser prints. [5]

Rich black is often regarded as a color that is "blacker than black". While this is impossible from the point of view of color theory, the difference can often be seen in the printed piece. The difference is most apparent in backlit (also known as "translite") pieces, where rich black more thoroughly blocks the light from coming through.

The use of rich black has to be based on a full understanding of the printing conditions, including the inks, printing press and especially the paper. If too much ink is used on poor quality paper such as newsprint, this may cause the paper to literally fall apart. In addition, excessive amounts of ink may not have a chance to fully dry before the printed result comes into contact with other pages. The additional ink used to create rich black also results in higher printing costs. [6]

Care must be taken when using electronic design programs (e.g. when managing a CMYK document in Adobe Illustrator or Corel Draw) – "black" may or may not equal 100%K depending on the CMYK profile specified in the image's settings, and Photoshop will represent the various tones using RGB values close to black; in an RGB document, "black" always equals RGB value (0, 0, 0). [6]

Another reason to use rich black for small areas of black is to avoid trapping issues. Rich black is often used for text printed over a picture or colored background, because otherwise any slight mis-registration between printing plates would produce a white or colored halo around the text, making it much harder to read. [2] [6] [7]

Related Research Articles

<span class="mw-page-title-main">Cyan</span> Color visible between blue and green on the visible spectrum; subtractive (CMY) primary color

Cyan is the color between blue and green on the visible spectrum of light. It is evoked by light with a predominant wavelength between 500 and 520 nm, between the wavelengths of green and blue.

<span class="mw-page-title-main">CMYK color model</span> Subtractive color model, used in color printing

The CMYK color model is a subtractive color model, based on the CMY color model, used in color printing, and is also used to describe the printing process itself. The abbreviation CMYK refers to the four ink plates used: cyan, magenta, yellow, and key (black).

<span class="mw-page-title-main">Primary color</span> Fundamental color in color mixing

A set of primary colors or primary colours consists of colorants or colored lights that can be mixed in varying amounts to produce a gamut of colors. This is the essential method used to create the perception of a broad range of colors in, e.g., electronic displays, color printing, and paintings. Perceptions associated with a given combination of primary colors can be predicted by an appropriate mixing model that reflects the physics of how light interacts with physical media, and ultimately the retina. The most common color mixing models are the additive primary colors and the subtractive primary colors.

<span class="mw-page-title-main">Magenta</span> Color

Magenta is a purplish-red color. On color wheels of the RGB (additive) and CMY (subtractive) color models, it is located precisely midway between blue and red. It is one of the four colors of ink used in color printing by an inkjet printer, along with yellow, cyan, and black to make all the other colors. The tone of magenta used in printing, printer's magenta, is redder than the magenta of the RGB (additive) model, the former being closer to rose.

<span class="mw-page-title-main">Laser printing</span> Electrostatic digital printing process

Laser printing is an electrostatic digital printing process. It produces high-quality text and graphics by repeatedly passing a laser beam back and forth over a negatively charged cylinder called a "drum" to define a differentially charged image. The drum then selectively collects electrically charged powdered ink (toner), and transfers the image to paper, which is then heated to permanently fuse the text, imagery, or both, to the paper. As with digital photocopiers, laser printers employ a xerographic printing process. Laser printing differs from traditional xerography as implemented in analog photocopiers in that in the latter, the image is formed by reflecting light off an existing document onto the exposed drum.

A page printer is a computer printer which processes and prints a whole page at a time, as opposed to printers which print one line or character at a time such as line printers and dot-matrix printers. Page printers are often all incorrectly termed “laser printers”—although virtually all laser printers are page printers, other page printing technologies also exist.

Pantone LLC is an American limited liability company headquartered in Carlstadt, New Jersey, and best known for its Pantone Matching System (PMS), a proprietary color space used in a variety of industries, notably graphic design, fashion design, product design, printing, and manufacturing and supporting the management of color from design to production, in physical and digital formats, among coated and uncoated materials, cotton, polyester, nylon and plastics.

<span class="mw-page-title-main">Gamut</span> Color reproduction capability

In color reproduction and colorimetry, a gamut, or color gamut, is a convex set containing the colors that can be accurately represented, i.e. reproduced by an output device or measured by an input device. Devices with a larger gamut can represent more colors. Similarly, gamut may also refer to the colors within a defined color space, which is not linked to a specific device. A trichromatic gamut is often visualized as a color triangle. A less common usage defines gamut as the subset of colors contained within an image, scene or video.

<span class="mw-page-title-main">Subtractive color</span> Light passing through successive filters

Subtractive color or subtractive color mixing predicts the spectral power distribution of light after it passes through successive layers of partially absorbing media. This idealized model is the essential principle of how dyes and pigments are used in color printing and photography, where the perception of color is elicited after white light passes through microscopic "stacks" of partially absorbing media allowing some wavelengths of light to reach the eye and not others, and also in painting, whether the colors are mixed or applied in successive layers.

<span class="mw-page-title-main">Xerography</span> Dry photocopying technique

Xerography is a dry photocopying technique. Originally called electrophotography, it was renamed xerography—from the Greek roots ξηρόςxeros, meaning "dry" and -‍γραφία-‍graphia, meaning "writing"—to emphasize that unlike reproduction techniques then in use such as cyanotype, the process of xerography used no liquid chemicals.

<span class="mw-page-title-main">Digital printing</span> Method of printing

Digital printing is a method of printing from a digital-based image directly to a variety of media. It usually refers to professional printing where small-run jobs from desktop publishing and other digital sources are printed using large-format and/or high-volume laser or inkjet printers.

<span class="mw-page-title-main">Offset printing</span> Printing technique

Offset printing is a common printing technique in which the inked image is transferred from a plate to a rubber blanket and then to the printing surface. When used in combination with the lithographic process, which is based on the repulsion of oil and water, the offset technique employs a flat (planographic) image carrier. Ink rollers transfer ink to the image areas of the image carrier, while a water roller applies a water-based film to the non-image areas.

Color printing or colour printing is the reproduction of an image or text in color.

<span class="mw-page-title-main">Gum printing</span> Chemical method of making photographic prints

Gum printing is a way of making photographic reproductions without the use of silver halides. The process uses salts of dichromate in common with a number of other related processes such as sun printing.

LightJet is a brand of hardware used for photographic printing of digital images to photographic paper and film. LightJet printers are no longer manufactured but are however remanufactured and resold; and their lasers are still manufactured.

<span class="mw-page-title-main">CcMmYK color model</span> Six-color printing process

CcMmYK, sometimes referred to as CMYKLcLm or CMYKcm, is a six-color printing process used in some inkjet printers optimized for photo printing. It complements the more common four color CMYK process, which stands for Cyan, Magenta, Yellow and Key (black), by adding light cyan and light magenta. Individually, light cyan is often abbreviated to Lc or c, and light magenta is represented as Lm or m.

<span class="mw-page-title-main">Inkjet paper</span> Paper designed for use with inkjet printers

Inkjet paper is a special fine paper designed for inkjet printers, typically classified by its weight, brightness and smoothness, and sometimes by its opacity.

<span class="mw-page-title-main">Specifications for Web Offset Publications</span>

Specifications for Web Offset Publications, invariably abbreviated to SWOP, is an organization and the name of a set of specifications that it produces, with the aim of improving the consistency and quality of professionally printed material in the United States, and of certain other products, programs and endorsements related to their work. Among other things, the organization specifies SWOP inks used in CMYK printing, colors of SWOP proofs, other physical qualities pertaining to printing. The organization publishes its own specification and ICC profile and runs a certification program.

<span class="mw-page-title-main">Color mixing</span> Producing colors by combining the primary or secondary colors in different amounts

There are three types of color mixing models, depending on the relative brightness of the resultant mixture: additive, subtractive, and average. In these models, mixing black and white will yield white, black and gray, respectively. Physical mixing processes, e.g. mixing light beams or oil paints, will follow one or a hybrid of these 3 models. Each mixing model is associated with several color models, depending on the approximate primary colors used. The most common color models are optimized to human trichromatic color vision, therefore comprising three primary colors.

<span class="mw-page-title-main">Shades of magenta</span> Varieties of the color magenta

The color magenta has notable tints and shades. These various colors are shown below.

References

  1. 1 2 R. S. Hodges (2003). The Guild Handbook of Scientific Illustration . John Wiley and Sons. ISBN   0-471-36011-2.
  2. 1 2 Koopman, Harry Lyman (2007). The Booklover and His Books. p. 6.
  3. Obermeier, Barbara; Chan, Ron (2006). How to Wow with Illustrator. Peachpit Press. p. 68. ISBN   9780132705080.
  4. Johansson, Kaj; Lundberg, Peter; Ryberg, Robert (2012). A Guide to Graphic Print Production. John Wiley & Sons. p. 332. ISBN   9781118184875.
  5. Batchelor, Bruce; Whelan, Paul (2012). Intelligent Vision Systems for Industry. Springer Science & Business Media. p. 12. ISBN   9781447104315.
  6. 1 2 3 Gatter, Mark (2010). Production for Print. Laurence King Publishing. p. 160. ISBN   9781856696999.
  7. Downs, Simon (2005). "Is it a book, is it a screen, no it's…—graphics and the interface in electronic paper". Digital Creativity. 16 (1): 31–32. doi:10.1080/14626260500147751. S2CID   5418426.