Print Marking Engine

The RIP (Raster Image Processor) and/or Controller feeds raster image data to the Print Marking Engine. While Print Quality may be as much a function of the RIP/Controller as of the Print Engine, Print Engine imaging characteristics are fundamental.

• Technology

  Numerous print engine technologies in addition to Inkjet and Laser include: Thermal Wax and Dye Sublimation, Solid Inkjet as well as Drop-on-Demand and Continuous (Hertz) Inkjet, Direct Charge and Photo Transfer Electrostatic (including LED imaging, Liquid Toning, Xerography and Electroink), wet-process Silver Halide (AgX) and Dry Silver Photography, etc.

  Spot Characteristics

  Characteristics on the individual imaging spot strongly limit the print quality of which a print engine is capable. Spot Characteristics may materialize as dropouts and fill-ins, edge smoothness, legibility, sharpness, highlight and shadow detail—when viewed in Text, Lines, Tints & Blends, Computer Graphics, and Images. Spot size, including shape, uniformity, satellites, etc. is critical. Print engine addressability can be used to enhance color depth, screening algorithms, and image smoothness as well as resolution.

  Artifacts

  Artfacts are those print engine characteristics that shouldn't be there—or at least shouldn't be visible, such as background noise and banding. Some artifacts, such as screening defects, may result from RIP processing in an attempt to overcome print engine limitations.

  Color & Registration

  Print engine characteristics are often different for black, primary colors, secondary colors, reverses, screened gray and screened color printing. A key example of why color is more than four times as complex as monochrome is the need for tight registration of the process colors.

  Density and Gamut

  The available contrast is a function of the Density range—the color depth difference between media white and maximum black or saturated color; Lightness is an alternate measure. The total color gamut limits or allows more saturated computer graphics, richer images, etc.

  Gloss

  While some desire glossy photographic prints, glossy text may reduce legibility. In particular, differential gloss—between different colors or between the media and imaged areas—detracts from print quailty.