A Windows UWP app (aka Modere, Metro, or Windows Store app) is a type of application that runs on Windows 10, Windows 8 and Windows RT, PCs and tablets. Unlike traditional Desktop (or classic) apps, a UWP app has a single, chromeless (i.e., no outside frame) window that fills the entire screen by default. On Windows 10, Modern apps can start in a Window, and if not full screen, tend to have a hamburger menu and a title in the upper left.
Printing of Windows 10 UWP app creates a large spool file
This issue occurs when you have a document open in a Modern App that contains images and text on multiple pages, for example, a PDF file and you try to print the file by using a PostScript or PCL6-based printer driver. Within the printer properties, you select the print feature to include more than one page per sheet. In this scenario when the print job is sent to the print queue, you may notice that the size of the print job is somewhat larger than the file size. WinPrint can do a variety of things with EMF jobs such as N-Up, Booklet printing, and Collation. Other custom print processors may provide more features. EMF requires more system resources because the print processor invokes the GDI/Printer driver to convert from GDI commands to the printer language. If a queue on a server accepts only RAW data type (in other words, the advanced printing features are disabled), then the conversion from GDI commands to PDL happens on the client. The print processor is not invoked at all on the client, hence the loss of advanced features. According to Microsoft, this issue is expected behavior as the spooled data has to be converted from XPS data to an Enhanced MetaFile (EMF). This is so that data can be converted by the GDI engine into the Printer Definition Language (PDL) data which the print device can then receive. To work around this issue, Microsoft suggests that you limit the size of the spooled data – print the documents from a desktop application as there will be no data conversion required for the print device.
