Represents the "BM" entry of the annotation dictionary object.

It is an optional entry defined as part of the PDF 2.0 specification.

It contains a string representing a PDF name object.

The PDF specification states that this item assumes a value of "Normal" if no value has been provided.

This item may take one of the following valid values:.

• Normal
• Compatible
• Multiply
• Screen
• Overlay
• Darken
• Lighten
• ColorDodge
• ColorBurn
• HardLight
• SoftLight
• Difference
• Exclusion
• Hue
• Saturation
• Color
• Luminosity

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 164, page 383.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 166, page 467.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 252, page 467.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 255, page 565.

The blend mode controls how the annotation is composited onto the page content beneath it, corresponding directly to the BM entry in a graphics state dictionary.