{{Short description|Type of ink or pigment used in printing}} [[File:RIAN archive 978876 Printing banknotes at Goznak factory in Perm.jpg|thumb|Printing Russian 5,000 ₽ banknotes with a metallic spot color]] In offset printing, 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 is produced by printing a series of dots of different colors.<ref>{{Cite web | title = What is the difference between spot and process colors? | url = http://www.pantone.com/help/?t=Process-color-vs.-Spot%2C-or-solid-color | url-status = deviated | archive-url = https://web.archive.org/web/20170820162600/http://www.pantone.com/help/?t=Process-color-vs.-Spot%2C-or-solid-color | archive-date = 2017-08-20 }}</ref>
The widespread offset-printing process is composed of the four spot colors cyan, magenta, yellow, and key (black) commonly referred to as CMYK. More advanced processes involve the use of six spot colors (hexachromatic process), which add orange and green to the process (termed CMYKOG). The two additional spot colors are added to compensate for the ineffective reproduction of faint tints 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, 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 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 == In print design, 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.<ref>{{Cite web | title = Design Tips and Techniques for Printing with Clear Dry Ink on the Xerox Color 800/1000 Presses | publisher = Xerox Corporation | url-status = dead | url = https://download.support.xerox.com/pub/docs/800_1000_DCP/userdocs/any-os/en_GB/DesignTips_CDI-Xerox800-1000Presses_SRA3_HR.pdf | archive-url = https://web.archive.org/web/20260103145025/https://download.support.xerox.com/pub/docs/800_1000_DCP/userdocs/any-os/en_GB/DesignTips_CDI-Xerox800-1000Presses_SRA3_HR.pdf | archive-date = 2026-01-03 | access-date = 2025-12-12 | year = 2010 | format = PDF | language = en-US | page = 2 | quote = Mask for strawberries created in Photoshop and feathered to create a soft edge. Clear applied in Photoshop by adding a spot channel. <!-- Editpr's note: The quoted text is concealed in the bottom-right corner by a solid-filled rectangle obstructing view. --> }}</ref> 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, passports, 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. Spot colors are frequently specified for brand identity (such as logos and marketing collateral) because the standardized inks can be matched consistently across different presses, print runs, and suppliers.<ref name="AdobeDiscover">{{Cite web | title = Learn the difference between spot color and process color | url = https://www.adobe.com/creativecloud/design/discover/spot-vs-process-color.html | website = Adobe Creative Cloud | publisher = Adobe Inc. | access-date = 2025-12-12 }}</ref><ref name="RMITSpot">{{Cite web | title = Process (CMYK) and Spot (Pantone) colour printing | url = https://rmit.pressbooks.pub/colourtheory1/chapter/spot-pantone-and-process-cmyk-colour-printing/ | website = Colour Theory: Understanding and Working with Colour | publisher = RMIT University | date = 2023-02-23 | access-date = 2025-12-12 | quote = Spot colour... uses pre-mixed colours... preferred when a small set of exact colours are needed... Some company logos require a very specific spot colour. }}</ref><ref name="GDPF">{{Cite book | author = Graphic Communications Open Textbook Collective | title = Graphic Design and Print Production Fundamentals | publisher = BCcampus OpenEd | date = 2015 | url = https://bdigital.uvhm.edu.mx/wp-content/uploads/2020/05/Graphic-Design-and-Print-Production-Fundamentals.pdf | format = PDF | pages = 128–130 | access-date = 2025-12-12 | quote = Pantone has developed a library of ink recipes... A designer … can be assured that documents... will be imaged with inks that have similar spectral values to the swatch books... The Pantone library was created to mix pigments for spot colour inks. }}</ref>
== 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, the dominant spot color printing system in the United States and Europe. * Toyo Ink, also known as the Toyo Color Finder System, is a spot color system common in Japan.<ref>{{Cite web | url = http://www.toyoink.com/ | title = Toyo Ink America, LLC | archive-url = https://web.archive.org/web/20240415194206/https://www.toyoink.com/ | archive-date = 2024-04-15 | url-status = dead }}</ref> * DIC Color System Guide, another spot color system common in Japan – it is based on Munsell color theory.<ref name="TII">{{Cite web | url = https://www.theinformedillustrator.com/2012/09/process-versus-spot-color.html | title = The Informed Illustrator: Digital Spot Color Systems | date = September 25, 2012 | language = en-US }}</ref> * ANPA color palette, a palette of 300 colors specified by the American Newspaper Publishers Association for spot color usage in newspapers. * 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).<ref name="gpi">{{Cite web | url = https://www.gpi.org/color-guides | title = GCMI Colors {{!}} GCMI Color Book | publisher = Glass Packaging Institute | language = en-US | access-date = 2026-05-16 }}</ref> * 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.
==References== {{reflist}}
==External links== * {{Webarchive|title=Spot and Process Colours Explained|url=https://web.archive.org/web/20241213080412/https://www.castleprint.co.uk/spot-and-process-colours-explained/|date=13 December 2024|nolink=yes}} * [https://pantonecolors.net/pantone-colors-finder/ Pantone Colors Finder]
{{Color topics}} Category:Color space Category:Printing terminology