Big spool files with Citrix UPD (EMF)

The Citrix universal printer driver (UPD) can generate big spool files. Printing within the LAN and big print data is not dramatic, but over WAN connection the print data can become a massive issue. Quite often printouts from Adobe documents but also other files like Word etc. can become very big.

How does it come to such big print data and how to avoid it? If you know about it, then you can reduce the size by 99%!

The spool files with Citrix UPD

When using the Citrix universal Printer driver (UPD) by default the Enhanced Metafile (EMF) Format from Microsoft is used. The EMF was enhanced and Extended by Citrix to optimize printing over wan connection. This feature was introduced with Presentation Server 4.5 and has been improved since then.

Even with all the optimization, big spool files can become huge. For example, a 9MB PDF files spooled with Citrix UPD based on EMF can grow up to 450MB and might have the travel over a WAN connection.

If you are using the max compression, you still will have 50% of the print data and therefore 225MB.

With Riverbed, Netscaler-SD WAN, etc. you might be able to reduce the size further but not very much, but the problem is something else. Microsoft EMF cannot handle rasta data and even worth it grows the spool file. Microsoft described the EMF problematic, and they say to disable EMF!

• The size of the EMF spool file may become very large when you print a document that contains lots of raster data
  https://support.microsoft.com/en-us/help/919543/the-size-of-the-emf-spool-file-may-become-very-large-when-you-print-a

Luckily the Citrix UPD is capable of using different formats like Microsoft XPS that is also optimized and has no issues with rasta data. Just move the XPS format at the top of the priority list within the Citrix policies, and the new default will be XPS with the UPD.

The same printout of the PDF document from before generates a spool file of just 3,77MB and in comparison with 450/225MB almost nothing. Sending 3,77MB over a WAN comnnection should not be a problem and quickly be done.

It's questionable why not to use the Citrix UPD with the XPS format as default in the future.