You can potentially reduce the print close time of a .NET deployed COBOL application that prints long documents by enabling the optimization for network printers via the Switch.System.Drawing.Printing.OptimizePrintPreview configuration switch.
This optimization is described in the PrintPreviewDialog performance section of PrintPreviewDialog control overview (Windows Forms) - https://docs.microsoft.com/en-us/dotnet/desktop/winforms/controls/printpreviewdialog-control-overview-windows-forms?view=netframeworkdesktop-4.8.
For example, for applications running on the .NET Framework versions 4.6 or later, you can add the following switch to the <AppContextSwitchOverrides> element in the <runtime> section of your application configuration file:
<runtime> <AppContextSwitchOverrides value="Switch.System.Drawing.Printing.OptimizePrintPreview=true"/> </runtime>