Most prepress companies or print shops use print spool systems and so-called Open Prepress Interface (OPI) servers to optimize their workflow. Helios Software GmbH is a well-known vendor of such software. With the standards set by the International Color Consortium (ICC) and with proper use of the Portable Document Format (PDF), as specified by Adobe, a consistent color managed workflow can now be implemented in server-based environments. The purpose of this article is threefold:1. There are ongoing discussions about where color matching should happen: in the print client's application, in the RIP of the final output device, or somewhere else? Helios advocates color matching and separation in the print spooler or the OPI system where the final destination of a print job is best known. The article tells why and how.2. Until recently, PDF could be used for electronic delivery and viewing on screen as well as for black & white printing, but not for color production. However, with proper server-based color matching and PDF support as e.g. with Helios PDF Handshake and Print Preview, perfect color printing of PDF documents on any PostScript device and even to non-PostScript printers like PC ink-jet printers becomes a reality.3. What makes a good output device a perfect fit in a server-based workflow? The article lists some features which allow smoother and more efficient print production.