Transparency group properties

The properties on the Transparency - Transparency group tab refer to the selection made on the Parent Transparency Group tab (highlighted in blue). If nothing is selected, the properties of the page are shown.

Property Meaning
Form is transparency group

Page is transparency group

Whether this option refers to 'form' or 'page' depends on your selection.

If cleared, the selected form is not a transparency group. The objects are rendered as if they were placed directly on the page. The options listed below are grayed out.

If enabled, the form is a transparency group and the settings selected here will be used to render the transparency group.

Knockout group If selected, the objects in the transparency group are rendered as one object. Overlapping parts cannot interact with each other: the objects on top fully overwrite the objects underneath.
Isolated group The objects in the transparency group are not affected by the objects underneath. For example, an ad is typically rendered as an isolated group before it's put in the magazine or newspaper in which it will be published.
Blending color space Only active if Isolated group is selected. Blending color space to be used for rendering the transparency group.
ICC Profile Only active if the blending color space is Gray, RGB or CMYK; in that case you can select the appropriate ICC Profile.
Note: Want to know more about transparency groups? Refer to the PDF Reference (e.g. illustrations on page 1147, plate 17).