The Rainbow Effect: Advancements in Color Printing
        
        
        
        Printing in color has become relatively inexpensive, but all color printers 
  are not the same. Here we’ve surveyed four distinct printer models ranging 
  from a low-cost model offering advancements for its price range to high-end 
  machines appropriate for networked printing.
The Epson Stylus C80 printer offers a breakthrough in ink technology. 
  The new DuraBrite Ink, in four individual cartridges (cyan, magenta, yellow, 
  and black), is a pigment ink, rather than traditional dye ink. The pigment ink 
  rests on top of the paper without bleeding or fading. Durable and water resistant, 
  it is ideal for wet lab use or for printing documents that might be used outdoors. 
  Individual cartridges mean that users need replace only the one that runs low, 
  rather than throw out an entire color cartridge when one color is depleted. 
  The cost of the three separate color cartridges is comparable to one three-color 
  cartridge.
  
The C80 also features Epson’s Micro Piezo technology, a process that injects 
  up to three different sized ink droplets, depending on the needs of the image. 
  The unit prints at an impressive 20 ppm (pages per minute) in black (10 ppm 
  in color), and features auto-edge smoothing, which enhances the look of low-resolution 
  documents like Web page printouts, and improves skin tone replication. The unit 
  is available in wired or wireless networking models. The duty cycle (number 
  of pages that can be printed per month before a user would have to be concerned 
  about equipment failure) is 5,000 pages. At $149 after a $30 rebate, this printer 
  offers a lot for the money. www.epson.com
  
The Xerox Phaser 860B uses single-pass solid ink technology to print 
  both black and color copies at 16 ppm. It lists for $1,999 and up, depending 
  on features. Although it and the other printers featured here list at a much 
  higher price than the Epson, the performance is also considerably higher. With 
  64 MB of RAM and a 5GB hard drive, the 860 offers network models and a duty 
  cycle of 65,000 pages per month, making it appropriate for shared-printer situations. 
  Xerox also supplies free black ink for the life of the printer, reducing overall 
  costs somewhat. Average costs per page range from 0.5 cents for a black-and-white 
  business letter to 1.1 cents for color. The cost increases as more ink covers 
  the page—when printing a color photo or graphic, for instance. The 860 
  uses Adobe Postscript language, an advantage for graphic arts uses, and the 
  Advanced ColorStix II ink provides improved page “feel” and more pages 
  per ink stick. www.xerox.com
  
The C7000 series from Oki Data, recently ranked the top 12-ppm laser 
  printer by PC World magazine, features single-pass color technology to 
  apply color in one pass using four LED print heads and image drums. In monochrome, 
  the printer operates at 20 ppm. The C7000 series uses oil-less toner, which 
  the manufacturer claims gives documents a more “elegant and translucent” 
  look.
With 64 MB of RAM and a 5GB hard drive, the unit is comparable in power 
  and memory to the Xerox 860B. Oki also includes 550-sheet second and third paper 
  trays and an optional automatic duplexer for two-sided printing—both important 
  for situations in which several people will share one printer. The C7000 series, 
  priced between $3,499 and $7,499, prints on a wide array of papers, including 
  card and index stock. www.okidata.com
  
The Riso RN2000, listing at $7,995, also serves as a copier and is the 
  most feature-rich of the products surveyed here. Users operate the machine via 
  an LCD user interface panel. The unit’s color array includes the usual 
  four colors plus burgundy, fluorescent pink, teal, and orange. The printer-duplicator 
  can be networked to allow users access from their desktops. This powerful machine 
  prints 60 to 130 ppm, depending on settings, has a paper capacity of 1,000 sheets, 
  and features zoom and reduction settings. Environmentally conscious buyers should 
  note that the RN2000 uses auto sleep and auto power off, prints well on newsprint 
  and recycled papers, and is free of ozone emissions, toxic fumes, flammable 
  liquids, and UV light. www.riso.com
  
  
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       Most printers use 
        a process called xerography, which involves exposing an electrically charged 
        photoconductor to light. The light causes the charged particles to dissipate, 
        creating the image that will be printed. Toner, tiny particles of plastic 
        dust, is attracted to the charged areas of the photoconductor, and then 
        transferred to paper by heat fusion. The printing process occurs using 
        one of three technologies. Laser printers rely on a laser beam 
        to bounce light off of a rotating mirror onto the photoconductor. LED 
        printers use semiconductor technology rather than lasers, complex 
        lenses, and mirrors. Fewer moving parts mean fewer mechanical breakdowns. 
        Solid ink printing, a proprietary technology available only in 
        some Xerox printers, uses specialized ink that remains solid until melted 
        by the heat of the printing process. Unlike water-based inks used in many 
        inkjet printers, solid ink is durable, water-fast, and vibrant. 
      Most printers use 
        four colors to print any color document, though some photo enthusiast 
        models use six. The ink is stored in cartridges and called forth as needed. 
        Usually, color is applied in a four-pass process: The photoconductor g'es 
        through four successive printing cycles to transfer the desired amount 
        of color, one at a time, to the page. For this reason, color printing 
        operates four times slower than monochrome (black) printing. However, 
        recently developed single-pass technology relies on four photoconductors 
        (as well as four lasers or LED imaging systems) to simultaneously print 
        all four colors, dramatically improving printing speed. While these printers 
        are more expensive than four-pass printers, the price difference is shrinking. 
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