Citrix Virtual Apps and Desktops

Citrix Universal Print Driver (UPD)

The Citrix Universal Print Driver (UPD) is not a single driver but a technology comprising components on both the server (VDA) and the client (endpoint with Workspace app).

  • Server Component: Installed with the VDA, this includes the actual generic print drivers, such as the “Citrix Universal Printer” (which uses the EMF format) and the “Citrix XPS Universal Printer” (which uses the XPS format), along with support for PDF and PS formats. Its role is to capture the print output generated by applications running on the VDA in a device-independent format.

  • Client Component: Included within the Citrix Workspace app installation, this component receives the print stream sent from the VDA. It then interacts with the local Windows printing subsystem on the endpoint device to render the print job using the appropriate device-specific driver installed locally for the target printer.

The following illustration shows the Universal Print driver components and a typical workflow for a printer locally attached to a device -

print-1

The primary goal of the UPD is to simplify printer driver management within the Citrix environment. By using a built-in driver on the VDA, administrators can avoid installing and maintaining potentially hundreds of different manufacturer-specific drivers, which are a common source of instability and conflicts. The UPD aims to be compatible with a wide range of printers, providing a universal interface between the virtual session and the client’s printing capabilities.

Supported Formats

The UPD technology supports several print data formats, allowing flexibility in how print jobs are processed and rendered:

  • EMF (Enhanced Metafile Format): The default format used by the “Citrix Universal Printer” driver. It’s a 32-bit Windows-native vector format. Printing using EMF is generally efficient but typically requires a Windows-based client endpoint for rendering.
  • XPS (XML Paper Specification): Used by the “Citrix XPS Universal Printer” driver. XPS is an XML-based page description language developed by Microsoft, similar in concept to PDF, designed to be platform-independent.
  • PS (PostScript): A page description language developed by Adobe, known for its capabilities in handling complex graphics and typography, often used in publishing and by various printers and multifunction peripherals. Linux clients often utilize PostScript printing with UPD.
  • PDF: PDF is a widely used open standard for document exchange. It encapsulates a complete description of a fixed-layout flat document, including the text, fonts, graphics, and other information needed to display it. It is designed to be platform-independent and is ideal for preserving document fidelity across different systems and applications.

Using the UPD offers several potential advantages:

  • Reduced Driver Management: Significantly decreases the number of drivers needed on VDA images, simplifying image creation and maintenance.
  • Improved Stability: Fewer drivers mean fewer potential conflicts and a lower risk of driver-related spooler crashes or system instability.
  • Optimized Print Jobs: Certain UPD formats, particularly EMF, can sometimes result in smaller print job sizes compared to native drivers.
  • Advanced Feature Support: The EMF and XPS UPD components can support advanced printing features (like stapling, tray selection) if the native driver on the client exposes these capabilities through Microsoft’s standard Print Capability technology.
Citrix Universal Print Driver (UPD)