Microsoft's new v4 driver technology uses the Microsoft XPS format, replacing the 25-year-old Enhanced Metafile (EMF) format. The XPS format is similar to a self-contained PDF file. Everything about the document such as fonts, images, and layout are all included in this one file. Each XPS document consists of a very organized structure that defines every aspect of the document. This new Microsoft XPS format is a huge improvement over the older EMF formats when it comes to portability and usability.
Starting with Windows 8, printing is processed via this new XPS technology. For backward compatibility with older printer drivers, Microsoft has added built-in converters to the operating system that convert XPS documents to EMF. Unfortunately, this additional step can cause conversion issues and printing delays depending on the layout, size, and color of the document. Drivers that work natively with the XPS format have fewer points of failure and improve future compatibility with printing applications.