11. Transparency

11.6 Specifying transparency in PDF

11.6.6 Transparency group XObjects

Change Table 145 as follows:

Table 145 -Additional entries specific to a transparency group attributes dictionary
Key Type Value
CS name or array


The group colour space shall be any device or CIE-based colour space that treats its components as independent additive or subtractive values in the range 0.0 to 1.0, subject to the restrictions described in 11.3.4, "Blending colour space". These restrictions exclude Lab and lightness-chromaticity ICCBased colour spaces, as well as the special colour spaces Pattern, Indexed, Separation, and DeviceN. Device colour spaces shall be subject to remapping according to the DefaultGray, DefaultRGB, and DefaultCMYK entries in the ColorSpace subdictionary of the current resource dictionary of the group XObject (see, "Default colour spaces").


Last modified: 20 March 2022