A new instance of this class is returned by the Repaginate(Double,Double) method. This method is particularly helpful when the sheets of an Excel document are large and displaying or printing each one as a single page is impractical or impossible.

The document can be created and processed in any thread with any apartment state - STA or MTA. But if it should be displayed as well, then there are some concepts which should be taken into account.

• In WPF display scale mode the document must be created in UI thread, otherwise System.InvalidOperationException will be thrown, stating that "The calling thread cannot access this object because a different thread owns it". This is requirement of Windows Presentation Foundation.
• In Native display scale mode, which is the default for ImageGear, there are no restrictions for displaying Excel documents in a multi-threaded environment.

System.Object
   ImageGear.Core.ImGearDocument
      ImageGear.Formats.Office.ImGearExcelSheetDocument

Reference