Dec 6, 2005
The Broadhurst Report
Technology: How Much Do You Really Know?
By Guy Broadhurst
Your data center, printshop, CRD--whatever you may call it-- is pulsing with technology. There are RIPs and networks and print engines and intelligent inserters. And it all works, at least most of the time. But how much do you really know about what goes on under the skins of all these green, beige, gray, and black boxes? And how much should you know? The answer is, enough to understand how the differences competing equipment can affect your business or operation.
It's a bit like your car. You don't need a hands-on knowledge of the SUV's inner workings to determine if the engine has enough power to haul your boat or camper; if there's enough room to haul your children and their friends; or if that red sports car's engine and suspension have what it takes to fulfill your need for speed. But you do need to understand the value of a big engine to haul the boat, the flexible seating to hold a tribe of rambunctious soccer players, and how an independent suspension will help when you accelerate out of a corner at tire-screeching speeds. You already know how to differentiate these things, along with the picture quality on competing TVs and a few dozen other products.
Some of the differences--and your judgments--may be subjective, or even based on brand preference, but if you look at key aspects of the underlying technology you can make a more informed decision. You don’t' have to understand the complexities of corotrons, photoconductors, or toner formulations, but you should know how certain technical characteristics of a given device may make it better suited for your operation. Two examples that come to mind revolve around print quality.
Imaging Technology
Electrophotographic printing basically uses light beams and positive and negative electrical charges to place images on a page. The light is generated either by lasers or LED printheads, but where the laser uses mirrors to project the image to the photoconductor drum, the LED projects it directly via a lens array. Both provide excellent image quality but the LED printhead provides more flexibility in print resolution. Laser printers are limited to a fixed resolution on a line by line basis.By comparison, a LED printer can be switched between 240, 300 and 600 dpi on the same line, providing greater flexibility for legacy applications that cannot be converted. This gives service bureaus and data centers more flexibility from a given print engine so more work can be performed for a smaller equipment investment. Additionally, reliability is much better for LED based machines as there are no moving parts. Also, when they fail, no adjustments are needed to get the printer up and running. Both of these result in less downtime and lower running costs in the long run.
The level of imaging technology rises sharply when color is involved. There are a lot of digital color presses on the market, differentiated by throughput speed, print quality and range of substrates that can be used. How the print engine places an image on a page is integral to these issues and is the technical piece you need to understand. Most EP color printers use translucent toner that's put down in layers, much like conventional printing inks, to achieve the colors desired. This requires setting the linescreen correctly and creates a traditional rosette of the four screen angles. The layers can be prone to cracking, however, and fusing them to the paper can slow printing substantially on the heavier substrates used for covers and direct mail pieces. By comparison, Océ's Direct Imaging and CopyPress technology uses a solid color toner which places each dot of toner directly adjacent to other dots to create the image. This stochastic (or FM) screening approach puts down only a single layer of toner, and the fusing process uses heat and pressure to press the image into the page, resulting in a smoother finished sheet with an offset look and feel. In addition, the press can run at full-rated speed regardless of the substrate used, the toner doesn't crack when folded, and can better withstand automated handling by the postal service than conventional toner.
Understand Software, too
Digital presses produce the physical pages, but getting jobs into production is the duty of workflow software. Take proofing, for example. This critical step once required a printed a version of a document but has steadily transitioned to "soft proofing" or viewing documents on-screen. What's important to understand is how the image you are viewing is created. Many proofing tools use a built-in Adobe Distiller to create a PDF, but as most document professionals know, incorrect Job Options can cause a PDF to print differently than it appears on-screen. A more reliable approach is using the same RIP that will prepare the actual file to produce a soft proof. This ensures the proof is identical to the print version, and also enables you to see both sides of a duplex page at the same time (especially important for book manufacturing) so you can check front-to-back registration. This TrueProof technology is what we at Océ have developed to provide faster and more reliable proofing for high volume environments.
There are many other examples of how understanding the different technologies can help you make better equipment and software investments. The point is, you don't need to be an expert, but knowing a little bit of what is going on "under the hood" makes you a smarter document professional and that has a bottom-line affect on your business or print operation.