The Spot color overprint option defines how two or more spot colors will behave when printed on top of each other.

Typically, when two different colored objects overlap, there is a knockout effect. The two different colored objects will not print on top of each other. Intentionally printing one layer of toner or ink on top of another is overprinting. The overprint setting defines how two or more spot colors will behave when printed on top of each other.

Higher overprint settings result in darker printouts. For example, an overprint value of 100% means that the colors will be completely added to each other. Lower overprint settings result in lighter printouts because colors appear more opaque and hide parts of other colors.

The Spot color overprint settings specify the different methods to add spot colors to a background color or on top of other spot colors. The selected setting for spot color overprinting defines the overprint behavior.

The following methods are available:

• Standard - The Standard setting uses CMYK addition. CMYK addition is the most common way of calculating the resulting color for either an overprint of two spot colors or an overprint of a spot color with process colors. The final channel values are the result of the per-channel addition of the values of background color and spot color.
• Vivid - The Vivid setting uses overprint calculation in L*a*b* or XYZ color space and uses numerical color values based on the actual color profiles of the output device. The Vivid setting is more accurate and avoids the typical clamping errors that sometimes occur with the Standard setting.
• Natural - The Natural setting allows you to merge the spot color channels into the process colors during document creation. This method converts all channels to RGB and then multiplies the R, G, and B components into a resulting RGB value.