Represents the "Shading" entry of the resource dictionary object.

It is an optional entry defined as part of the PDF 1.3 specification.

It contains an Element.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 33, page 83.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 34, page 112.

The Shading entry maps resource names to shading dictionaries. A content stream paints a named shading using the sh operator, which fills the current clipping region with the shading's color gradient.