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

Normally, when two different colored objects overlap, there is a knock-out effect. They will not print on top of each other. Intentionally printing one layer of ink on top of another is known as overprinting. The overprint setting defines how two or more spot colors will behave when printed on top of each other.

A higher setting results in a darker printout. For example, an overprint value of 100% means that the colors will be completely added to each other - something that is not possible on a proper printer or press. A lower setting results in lighter printouts because colors appear more opaque and hide parts of other colors.

The Spot color overprint print option settings specify the different methods that can be used to add spot colors to a certain background color or on top of other spot colors. The method used for the spot color overprint defines the overprint behavior.

The following methods are available:

• Standard – The Standard setting uses CMYK addition which is the most common way of calculating the resulting color for an overprint of two spot colors or 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. It is more accurate and avoids the typical clamping errors that can be seen with the Standard setting.
• Natural – The Natural setting allows the spot color channels to be merged into the process colors by the user during document creation. With this method, all channels are converted to RGB and then the R, G, and B components are multiplied into a resulting RGB value.