- Spot color
In
offset printing , a spot color is any color generated by anink (pure or mixed) that is printed using a "single run".The widely-spread
offset printing process is composed of four spot colors:Cyan ,Magenta ,Yellow and Key (black) commonly referred to asCMYK . More advanced processes involve the use of six spot colors (hexachromatic process), which add Orange andGreen to the process (termed CMYKOG). The two additional spot colors are added to compensate for the inefficient 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 asmetallic ,fluorescent , spot varnish, 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 samelithographic plate . Thedot gain , hence thescreen angle andline frequency , of a spot color vary according to its intended purpose. Spotlamination 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 asAdobe InDesign ,Adobe Illustrator ,QuarkXPress andScribus 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 you add more spot colors, due to the increased cost and complexity of added process inks and films, and requiring more runs per finished print. However, spot colors can be a very powerful weapon in security printing, like
money ,passport s, bonds, and other similar prints that should be hard to forge. Money printing for example, uses secret formulae of spot colors, some of which can be seen by the naked eye, and some cannot be seen unless by using special lights, or by applying certain chemicals.Digitization
Spot colors are now a great business for a company like Pantone. The modern trend in spot color matching systems is the digitization of spot colors. This idea came from the fact that a spot color print won't be a match to the monitor's colors, due to the inherent differences in printed (ink) colors and monitor (light) colors. To achieve a rather good result of simulating the RGB colors into CMYK colors in offset prints, a proper
monitor calibration should be done to realize a good balance between reproduction of gray color on paper and on screen.Classification
Spot color classification has led to hundreds of discrete colors being given unique names. There are several industry standards in the classification of spot color systems, such as:
*Pantone , the dominant spot color printing system in theUnited States andEurope .
* Toyo, a common spot color system inJapan .
* DIC, another common Japanese spot color system.
* ANPA, a palette of 300 colors specified by the American Newspaper Publishers Association for spot color usage innewspapers .
* HKS is a color system which contains 120 spot colors and 3250 tones for coated and uncoated paper. HKS is an abbreviation of three German color manufacturers: Hostmann-Steinberg Druckfarben, Kast + Ehinger Druckfarben und H. Schmincke & Co.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.See also
*
CMYK color space and printing (also called "process color")
*color
*color printing
*four-color printing
*printing
*Spreading and choking External links
* [http://www.myjanee.com/PSRL/PStips6.htm#monitorcalibration Monitor Calibration (Written by: Mohamed Al-Dabbagh)]
* [http://www.facemediagroup.co.uk/?page=spot_colour_vs_pantone Article on Pantone spot color vs. process colors]
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