How a viewer lays the pages out when the document opens: the catalog's PageLayout entry.
public enum PdfPageLayout
ISO 32000-2 §7.7.2, Table 29. The default is SinglePage.
kind:method, kind:property, kind:ctor. Press Esc to clear.OneColumnThe pages in one column (OneColumn).SinglePageOne page at a time (SinglePage, the default).TwoColumnLeftThe pages in two columns, odd-numbered pages on the left (TwoColumnLeft).TwoColumnRightThe pages in two columns, odd-numbered pages on the right (TwoColumnRight).TwoPageLeftTwo pages at a time, odd-numbered pages on the left (TwoPageLeft, PDF 1.5).TwoPageRightTwo pages at a time, odd-numbered pages on the right (TwoPageRight, PDF 1.5).