HP Scitex FB6100 Printing Technologies - Page 4

Display permanence claims are based on predictions from standardized, accelerated tests following HP, ISO, ASTM, and Wilhelm Imaging Research protocols. These claims are intended to give guidance for choosing an ink technology and print medium selection. Display permanence depends on actual display conditions for the print, and the amount of UV light in the display environment has a predominant effect on fading. While longer display permanence is generally considered a virtue, economical print production dictates that the useful life for the print in its actual display environment be carefully factored into the choice of ink technology and printing material. Realistically, not every print needs to last 2-3 years outdoors or more than 200 years on indoor display. For more information on how the choice of ink technology and printing material affects display permanence, visit www.hp.com/go/supplies/printpermanence . Color Writing Systems The hardware for an inkjet writing system involves the inks and printheads that produce an image on the print medium,2 which can be paper, vinyl, textiles, banner materials, cardboard, plastics, and other materials. When ink chemistry requires curing inside the printer, the writing system also includes components for the curing process. For example, UV-curable inks require high-intensity ultraviolet lamps to solidify the ink. HP Latex Inks require internal heat and forced air systems to evaporate volatile ink components and coalesce latex particles into a durable film. Both UV-curable inks and HP Latex Inks produce prints that are dry and ready to use out of the printer. Writing systems are typically described by the type and number of inks and the printhead technology. Inks are designated by their chemistry (aqueous, solvent, or UV-curable), their colorant (pigment or dye), and their color. For example, an 8-ink printer has an ink delivery system and printheads that accommodate eight inks. For application versatility, some 8-ink printers can be operated in 4-, 6-, or 8ink modes depending on a print job's requirements for image quality, production rate, and economy. Writing systems for HP's commercial and industrial printers are based on either HP Thermal Inkjet printheads or piezo printheads. HP Thermal Inkjet printheads are used in HP Designjet printers with aqueous inks and HP Latex Inks. HP Scitex printers use piezo printheads for aqueous, solvent, and UVcurable inks. Inks are used in a subtractive color system where colored layers are applied over a white substrate. Combinations of different inks produce a desired color by absorbing (subtracting) certain wavelengths from the light reflected from the substrate. The color of the substrate and the color of the illuminant both affect the printed color. The primary colors in subtractive color printing are cyan, magenta, and yellow. Most colored inkjet inks are transparent3, and this allows them to produce colors that are mixtures of these primaries (e.g., red = magenta + yellow, etc.) by printing one dot of ink on top of another: "doton-dot". Original HP inks for commercial and industrial applications are designated by a one or two letter system as shown in the table below. Following industry practice, "K" represents black ink. HP uses "G" for gray and "Gn" for green inks. C: cyan M: magenta Y: yellow G: gray K: black R: red W: white lc: light cyan lm: light magenta ly: light yellow lg: light gray lk: light black Gn: green pK: photo black B: blue mK: matte black E: Gloss Enhancer 2 This is the printing material, also called the "substrate". The substrate is the material and surface on which the image is formed. 3 Except, typically, black and white inks. 4