In offset printing, the spot color is any color of ink (pure or mixed) that is printed through a separate run of a sheet of paper in a printing device.
Widespread offset printing consists of four colors: blue-green (Cyan) , magenta (Magenta) , yellow (Yellow) and key color, black ( Black ), also known as the CMYK model . More advanced technologies include the use of six colors (hexachromatic) with additional orange and green colors in the printing process (abbr. CMYKOG). Two additional spot colors are added to compensate for the inefficient printing of dull inks with CMYK colors alone. However, offset printing professionals around the world use the term spot color as any color formed by non-standard offset inks (such as metallic, fluorescent , or any manually mixed ink).
For multi-color printing using spot colors, each spot color needs its own lithographic layer. All areas of the same spot color are displayed using the same layer, and therefore, using the same lithographic plate.
Content
Computer Methods
There are various methods for incorporating fairly complex spot color patterns at the end of prepress . Software applications such as Adobe InDesign , Adobe Illustrator , CorelDRAW , QuarkXPress, and Scribus can create spot colors as additional channels. Adobe Photoshop can also be used to create soft edges (commonly known as shaded edges) for spot colors. The dissolve effect provided in Adobe Photoshop layer preforms can be used to create any spot color.
Usage Optimization
As a rule, the amount of costs and possible problems when printing increases with the addition of additional spot colors. This is due to the increase in the cost and complexity of the process of creating added ink and film and the increase in the number of runs before obtaining a finished print. However, due to the more complex process, spot colors are effective in preventing counterfeiting of money , passports , bonds, and other important documents. For example, when printing money, secret formulas of spot colors are used, some of which can be seen with the naked eye, and some can be seen only with the help of special illumination or with the use of certain chemicals.
Classification
The spot color classification includes thousands of individual colors with unique names and numbers. There are several industry standards for spot color classification:
- Pantone, the leading spot color printing model in the US and Europe .
- Toyo, the general model of colors in Japan .
- DIC Color System Guide, another spot color printing model common in Japan, based on the Mansell color system . [one]
- ANPA, a palette of 300 colors set by the American Association of Newspaper Publishers as a spot color for use in newspapers .
- GCMI, the standard for colors used in printing on packaging developed by the Glass Packaging Institute (formerly known as the Glass Container Manufacturers Institute, hence the abbreviation).
- HKS is a color model that contains 120 colors and 3250 tons for coated and uncoated paper. HKS is the abbreviation of three German flower manufacturers: Hostmann-Steinberg Druckfarben, Kast + Ehinger Druckfarben and H. Schmincke & Co.
- RAL is the color standard used in Europe. The so-called classic RAL system is mainly used for varnish and powder coatings.
Due to the fact that each color system creates its own color from scratch, spot colors from one system may not be in the collection of another.
See also
- CMYK
- Colour
- Four-color printing
- Trapping