Sign & Digital Graphics

2012 Buyers Guide

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Free Radical UV Curing—The most common form of UV-curing ink chemistry, it employs a free radical reaction whereby a photoinitiator absorbs UV energy and generates an unpaired electron, beginning a chemical chain reaction (crosslink) with a double bond substance (monomers), causing the polymerization of UV ink. In free radical UV curing, the reaction ceases once the ink is no longer exposed to UV energy. Friction Feed—Process where material is fed through a printer or plotter by placing it between a motor-driven grit wheel and two tensioned pinch rollers. FTP (File Transfer Protocol)—A standard protocol for transferring data over the Internet. To use FTP, FTP software must be set up on both sending and receiving ends of an FTP transmission, and the client (initiator) must have a username, password and a valid target address on the server. FTP Server—A computer that can receive requests for an FTP link from a client machine, or the software on that machine that allows it to do so. This includes FTP server capability. Also called an FTP host. See also IIS. G Galvanized—Steel or iron that has been protected by a zinc coating. Galvanic Isolation—No electrically conductive path from the AC input to the DC output. This is a safety feature to prevent shock should a person come in contact with a broken LED in a sign. Gamma—Measurement of the degree of contrast between the lightest and darkest tones of an image. Gamma is also noted as the slope of a curve in measurements of color values, and can be altered for display and output. Gamut Compression—Electronic editing of an image so that it can be displayed or output within the limits of a particular device. Gantry—Bridge on which the spindle assembly of certain computerized routers and engravers travels. The spindle usually travels along the length of the gantry for X-axis movement. The gantry may also be mounted on rails for movement along the Y-axis; with other machines, the gantry is stationary and the table itself moves along the Y-axis. This term is also used in inkjet printing to describe the bridge on which a scanning printhead assemblies is housed on certain fl atbed printers. Gauge—A method for measuring the thickness of sheet metal. In the sign industry, most sheet metal ranges from 10-26 gauge. GCR (Gray Component Replacement)—This is a color separation process in which black ink is used to replace cyan, magenta, and yellow (CMY) in mid-tone and highlight areas where the three inks overlap, in order to reduce ink consumption and drying time. Similar to UCR. Genlock—In electronic digital signage, a video device that synchronizes two video signals and enables them to be mixed; for example, to overlay a subtitle produced on the computer onto live video. Gilding—The application of thin metal sheets to glass and other surfaces. See also Gold Leaf. Glass Sleeves—On some neon tube installations, clear glass units designed to add insulation to the electrodes and other wiring. Gold Leaf—Gold manufactured into thin leaves, commonly available in a range of from 10-23 karats. Gradation—Transition between colors or shades, created by mixing percentages of a dominant and secondary color and then altering them in steps to create the change. Grit Wheel—The motor-driven roller that moves material through a friction-feed plotter. Grommet—A reinforced metal eyelet found in banners used to receive cords or other fasteners. GTO—A type of insulated wire capable designed to handle the high voltages on the secondary circuits of neon signs. H Halation—A spreading or refl ection of light, a halo-like effect, produced by cove lighting or reverse channel letters. Halftone—The process of converting images into dots of various sizes with equal spacing between centers. Halo—A ring of light. Usually refers to the refl ection of light achieved by reverse channel letters, which appear to be ringed by light because the light source is refl ecting on the background from which the letters are pegged-out. HDPE (High-Density Polyethylene)—A strong, relatively opaque form of polyethylene having a dense structure. HDTV (High Defi nition TV)—The next generation of video content, capable of almost three times the clarity and resolution of standard NTSC broadcasts. HDU (High-Density Urethane)—A type of hard foam product used in sign production. Urethane has the density and fabrication characteristics of wood, but only one-third of the weight. Head-End—An installation that is the fi nal point from which video feeds for multiple channels are sent to broadcast or cable television customers. In addition to transmitting equipment, a head-end can contain feeds for various channels. Header—A separate board above the rest of a sign that gives it a headline or contains a different advertising message for the same product. Most often seen with point-of-purchase advertising. Heartbeat—In an electronic digital signage network, a brief status message sent to the network manager machine at regular intervals by a running media player, for health monitoring purposes. Heat-activated Adhesive—A type of adhesive used on some fi lm laminates that is not sticky at room temperature but softens when heated, thus activating the adhesive. Heat Bending—The process of heating PVC boards and then bending them to desired shapes. Heat Sink—A piece of thermally conductive material attached to a semiconductor or other electronic device (such as an LED), to conduct heat away from the device. Mid-June 2012 75

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