Support for Spot Colours

[duncangroenewald]

Does anyone know if there is support for Spot colours - often required in print shops for printing, for example, white on black stock.

The PDF specification has a specification for Colour Separations, often known as Spot Colours. Typically the spot colour is given a specific name and the print shop will recognise that name and use the appropriate plate with ink - these are solid colours and cannot be printed using CMYK inks.

Below is an extract from the PDF specification

8.6.6.4 Separation Colour Spaces
A Separation colour space (PDF 1.2) provides a means for specifying the use of additional colorants or for
isolating the control of individual colour components of a device colour space for a subtractive device. When
such a space is the current colour space, the current colour shall be a single-component value, called a tint,
that controls the application of the given colorant or colour components only.

A Separation colour space is defined as follows:
[ /Separation name alternateSpace tintTransform ]
It shall be a four-element array whose first element shall be the colour space family name Separation. The
remaining elements are parameters that a Separation colour space requires; their meanings are discussed
below.