RIAN archive 978876 Printing banknotes at Goznak factory in Perm

offset printing Offset printing is a common printing technique in which the inked image is transferred (or "offset") 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 ...

, a spot color or solid color is any color generated by an ink (pure or mixed) that is printed using a ''single run'', whereas a

process color The CMYK color model (also known as process color, or four color) 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 ...

is produced by printing a series of dots of different colors. The widespread offset-printing process is composed of the four spot colors

cyan Cyan () is the color between green and blue on the visible spectrum of light. It is evoked by light with a predominant wavelength between 490 and 520 nm, between the wavelengths of green and blue. In the subtractive color system, or CMYK col ...

magenta Magenta () is a color that is variously defined as pinkish- purplish- red, reddish-purplish-pink or mauvish- crimson. On color wheels of the RGB (additive) and CMY (subtractive) color models, it is located exactly midway between red and bl ...

yellow Yellow is the color between green and orange on the spectrum of light. It is evoked by light with a dominant wavelength of roughly 575585 nm. It is a primary color in subtractive color systems, used in painting or color printing. In ...

, and key (

black Black is a color which results from the absence or complete absorption of visible light. It is an achromatic color, without hue, like white and grey. It is often used symbolically or figuratively to represent darkness. Black and white ha ...

) commonly referred to as

CMYK The CMYK color model (also known as process color, or four color) 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'' refer ...

. More advanced processes involve the use of six spot colors ( hexachromatic process), which add orange and

green Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 Nanometre, nm. In subtractive color systems, used in painting and color printing, it is created by ...

to the process (termed CMYKOG). The two additional spot colors are added to compensate for the ineffective reproduction of faint

tints In color theory, a tint is a mixture of a color with white, which increases lightness, while a shade is a mixture with black, which increases darkness. Both processes affect the resulting color mixture's relative saturation. A tone is prod ...

using CMYK colors only. However, offset technicians around the world use the term ''spot color'' to mean any color generated by a non-standard offset ink; such as metallic,

fluorescent Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, th ...

, or custom hand-mixed inks. When making a multi-color print with a spot color process, every spot color needs its own lithographic film. All the areas of the same spot color are printed using the same film, hence, using the same lithographic plate. The dot gain, hence the screen angle and line frequency, of a spot color vary according to its intended purpose. Spot

lamination Lamination is the technique/process of manufacturing a material in multiple layers, so that the composite material achieves improved strength, stability, sound insulation, appearance, or other properties from the use of the differing materials ...

and UV coatings are sometimes referred to as 'spot colors', as they share the characteristics of requiring a separate lithographic film and print run.

Computer methods

There are various methods to incorporate rather sophisticated patterns of spot colors in the final prepress artwork. Software applications such as Adobe InDesign, Adobe Illustrator, CorelDRAW, QuarkXPress and Scribus may generate spot colors as additional channels. Adobe Photoshop can also be used to generate soft edges (widely known as feathered edges) of spot colors. The dissolve effect provided by Adobe Photoshop layer patterns can be generated for any spot color.

Optimizing usage

Generally the cost and potential for problems for a print job increase as one adds more spot colors, due to the increased cost and complexity of added process inks and films, and requiring more runs per finished print. However, because of the complicated process, spot colors are effective at preventing forgeries of

money Money is any item or verifiable record that is generally accepted as payment for goods and services and repayment of debts, such as taxes, in a particular country or socio-economic context. The primary functions which distinguish money ar ...

passport A passport is an official travel document issued by a government that contains a person's identity. A person with a passport can travel to and from foreign countries more easily and access consular assistance. A passport certifies the perso ...

s, bonds and other important documents. Money printing for example, uses secret formulae of spot colors, some of which can be seen by the naked eye and some that can only be seen by using special lights or applying certain chemicals.

Classification

Spot color classification has led to thousands of discrete colors being given unique names or numbers. There are several industry standards in the classification of spot color systems, such as: *

Pantone Pantone LLC (stylized as PANTONE) is a limited liability company headquartered in Carlstadt, New Jersey. The company is best known for its Pantone Matching System (PMS), a proprietary color space used in a variety of industries, notably graph ...

, the dominant spot color printing system in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

and

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...

. * Toyo, a common spot color system in Japan. * DIC Color System Guide, another spot color system common in Japan – it is based on Munsell color theory.The Informed Illustrator: Digital Spot Color Systems
/ref> * ANPA, a palette of 300 colors specified by the American Newspaper Publishers Association for spot color usage in

newspapers A newspaper is a periodical publication containing written information about current events and is often typed in black ink with a white or gray background. Newspapers can cover a wide variety of fields such as politics, business, sport ...

. * GCMI, a standard for color used in package printing developed by the Glass Packaging Institute (formerly known as the Glass Container Manufacturers Institute, hence the abbreviation). * HKS is a color system which contains 120 spot colors and 3,250 tones for coated and uncoated paper. HKS is an abbreviation of three German color manufacturers: Hostmann-Steinberg Druckfarben, Kast + Ehinger Druckfarben and H. Schmincke & Co. * RAL is a color matching system used in Europe. The so-called RAL CLASSIC system is mainly used for varnish and powder coating. Because each color system creates their own colors from scratch, spot colors from one system may be impossible to find within the library of another.

External links

Spot and Process Colors Explained

Creating color swatches or samples to match spot colors

References

{{color topics Color space Printing terminology