For as long as Terminal Servers have existed printing has been one of the biggest challenges when administrating a Server Based Computing environment. To solve these problems several manufacturers developed printing products. These products are all based on a Universal Printer Driver. But what’s universal in this driver? In this article I will explain the differences between several Universal Printer Drivers and show some of the key features in the universal printing products.
Types of Universal Printer Drivers
The term Universal Printer Driver does not mean that all the drivers are universal in the sense that they use the same techniques. The term Universal means that the driver can be used for almost every printing device. When comparing the different printing solutions three types of printer drivers can be distinguished.
1) Universal Printer Driver based on a normal basic printer driver
This was the first printer driver available as a Universal Printer solution. This type of universal printer driver uses a normal standard driver. Often the drivers used are HP drivers like the HP Laserjet 4/5 for black/white printing and the HP Laserjet 4500 for color printing. The printer job is handled and transferred like all common printer drivers.
This is not actually a universal printer driver, but just a replacement driver that will be assigned to other printing devices. This type of driver is, as mentioned, the first type of universal driver and is reaching its end of life.
Citrix used this kind of universal printer driver in former versions of Metaframe/Presentation server (till version 4) and a few full SBC products still use this kind of driver. The Microsoft Fallback driver is also based on this type of universal printer driver.
The advantages of this kind of driver are that it is usually available in the product you have already bought, so no additional investment is needed, and it is easy to maintain.
Because the driver is actually a driver from one of the manufacturers, it does not support all printing devices and has limitations with the tray support and duplex sessions.
2) Universal Printer Driver based on the EMF format
EMF is the Windows format for rendering the print job. The EMF file is normally created by the printer driver and sent to the Windows spooler.
Using the EMF driver the print job will be transferred into the Windows printer format by the printing product to the client. On the client the printer product client receives the EMF file and sends it to the client spooler.
Because EMF is only available within the Windows platform it can only be used by Windows based clients. Also EMF files are usually bigger than PDF based files.
EMF files are rendered for the printing device on the client, so the server has less work. On EMF the job keeps its original quality.
Examples of producta that use EMF are Citrix Presentation Server 4, Thinprint and Tricerat (Tricerat uses its own format based on EMF).
3) Universal Printer Driver based on the PDF format
The last common universal driver is based on Adobe’s PDF format.
Using this technique the printing solution renders the EMF file created by the local print spooler into a PDF or sometimes a PCL file. This file is sent to the client where the printing solution client renders the file into the EMF format so the spooler can send the job to the printing device.
The PDF/PCL format is available on most systems, so you do not need to have a Windows based client for this universal printer driver. Also the file is usually smaller than an EMF file so less bandwidth will be used.
Using a PDF solution the job is rendered on the server instead of the client. Also PDF compression affects the print quality. Printing features also depend on the PDF driver being used, while EMF depends on the features available in the client printer driver.
Uniprint and Net2Printer both use the PDF format.
The Provision Network printing product, Print-IT, supports both the PDF and the EMF format.
Citrix Printing solution against third party products
As described above, Citrix was using an alternative printer driver as a Universal Printer driver. Because this did not solve all problems, several third party products were introduced on the market. With Presentation Server 4 Citrix introduced their real Universal Driver solution using the EMF format. The main question during the introduction was if there were still situations were you needed an additional printing product. The printer product manufacturers quickly released white papers where they compared their product with the Citrix implementation and mentioned the advantages of their products.
In the article Can Third Party Software Solve Terminal Server Printing Problems I had described situations where a third party product should be used, so I will not go into those details now.
Considerations choosing a product
In most comparisons and also in the section above, I explained the difference between how EMF and PDF drivers work and the method of how auto created client printers are used. If your clients are in the same LAN, it (in my experience) is not always necessary to send the job first to the client because the client only has server print queues defined. In this case the print job would travel twice around the network. Most network printer products have a built-in feature or an optional module whereby the server side of the product sends the job directly to the print server in your infrastructure. This way you do not need a client for the product to be installed on your client machines.
On the other hand, you could have a central data centre where the server resides and your clients are located on several sites connected using a WAN. In this situation, compression and bandwidth control are important factors. Probably a PDF based product has benefits, although all products have compression and bandwidth control options. In this situation you should think about your print server functionality. All products deliver the print job to a spooler component that sends the job to the print device. This part of the total print process is not covered by any product so it travels uncompressed and uncontrolled over your network. In this kind of WAN situation this print component should preferably be located on the client side. Therefore, several products deliver a kind of print gateway.
All the products have their special features and solutions. It is a pretty tough market where the several manufacturers compare their products in white papers regularly. I have included a list of comparison documents at the end of the article.
This article was an introduction into the world of Universal Printing solutions. Three types of universal printer drivers are currently available:
- Using a default normal driver
- EMF based technology
- PDF based technology
Nowadays EMF and PDF based solutions are the standard (certainly now that Citrix has an EMF based solution). Both techniques have their advantages and disadvantages. Depending on your infrastructure you should choose the driver which has the most benefits.
If you are considering a product use this article and the comparison charts mentioned to perform your preliminary analysis. You should then download a few products and test them thoroughly in order to make your final decision.
Comparison White Papers:
Uniprint Overall Comparison (Uniprint, ThinPrint, Tricerat and Citrix PS4)