Sign & Digital Graphics

October '17

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S I G N & D I G I T A L G R A P H I C S • October 2017 • 33 DIGITAL PRINTING AND FINISHING DIGITAL GRAPHICS Paper, Please With so many varieties to choose from, it pays to know the characteristics of this popular substrate Stephen Romaniello is an artist and educa- tor who has been teaching digital art at Pima Community College in Tucson, Arizona, for more than 25 years. He is a certified instructor in Adobe Photoshop and has authored numerous books and articles on the creative use of digital graphics software. Steve is the founder of GlobalEye systems, a company that offers training and consulting in digital graphics software and creative imaging. B Y S T E P H E N R O M A N I E L L O The Digital Eye them into flexible sheets. It has so many uses, including writing, printing, packaging, cleaning, and hundreds of industrial and construction related processes that it's impossible to imagine a world without paper. A Brief History The word "paper" is derived from the Latin word papyrus— a thick, paper-like material produced from the pith of the Cyperus papyrus plant. Papyrus was used in ancient Egypt and other Mediterranean cultures for writing, but the oldest known archaeological fragments of the immediate precursor to modern paper, date to the 2nd Century BC in China. Before the indus- trialization of paper production, the most common source of fiber was from rags made of hemp, linen or cotton. With the introduction of wood pulp as a fiber source in 1843, paper pro- duction was no longer dependent on recycled rags. Today, there are countless varieties of paper used for printing. The characteristics of these substrates vary substantially and affect the vibrancy, contrast, texture and durability of the print. Wood Pulp Many papers start out as trees. They are made from wood, which contains cellulose and lignin (an organic polymer). To make pulp from wood, a chemical pulping process dissolves lignin in a cooking slurry so that it may be washed from the cellulose to preserve the length of the cellulose fibers. The pulp fibers are poured onto an open mesh screen called a "deckle" and then pressed and dried into paper. When pressed together, the fibers interweave at a microscopic level producing a smooth, level surface. Standard Office Bond Probably the most common paper you're likely to encoun- ter—I'll call it "Standard Office Bond" (SOB)—is a relatively inexpensive substrate and is normally used with the dry toner- based media typically used in copy machines and laser printers (see Figure 1). This paper does not usually get wet. Because of its porosity, moisture tends to wick through the fibers, and spread. Using SOB for inkjet printing absorbs pigment, producing fuzzy edges, poor color gamut and muddy colors. In addition, large ink deposits from graphics or photos soak the paper fibers, become swollen with moisture and then contract, resulting in waves and buckling of the paper surface as shown in Figure 2. Laser printers use heat to melt a solid powder (toner) onto the paper, therefore, standard office paper must be able to with- P aper! The thin material we encounter every day in some form or other is produced by pressing together moist fibers of cellulose pulp derived from wood, rags or grasses, and drying Figure 1: Standard office bond is a common medium for your copier or laser printer. Figure 2: A comparison of standard office bond (left) and glossy photo paper (right) printed on an inkjet printer. Standard office bond absorbs pigment and produces fuzzy edges, poor color gamut and muddy colors. Ink deposits easily soak the paper fibers and result in buckling of the paper surface.

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