Specifies the paper size of the PDF document. The default "auto" means paper size is determined by content.
The size of the content in pixels will match the size of the output in points (1 pixel = 1/72 inch).
- A predefined size. The supported paper sizes are: A0-A10, B0-B10, C0-C10, Executive, Folio, Legal, Letter, Tabloid.
- An array of two numbers specifying the width and height in points (1pt = 1/72in)
- An array of two strings specifying the width and height in units. Supported units are "mm", "cm", "in" and "pt".