Chapter 7. Printers and Printing Printers are an essential resource for creating a hard copy -- a physical depiction of data on paper -- version of documents and collateral for business, academic, and home use. Printers have become an indispensable peripheral in all levels of business and institutional computing. This chapter discusses the various printers available and compares their uses in different computing environments. It then describes how printing is supported by Red Hat Enterprise Linux. 7.1. Types of Printers Like any other computer peripheral, there are several types of printers available. Some printers employ technologies that mimic manual typewriter-style functionality, while others spray ink on paper, or use a laser to generate an image of the page to be printed. Printer hardware interfaces with a PC or network using parallel, serial, or data networking protocols. There are several factors to consider when evaluating printers for procurement and deployment in your computing environment. The following sections discuss the various printer types and the protocols that printers use to communicate with computers. 7.1.1. Printing Considerations There are several aspects to factor into printer evaluations. The following specifies some of the most common criteria when evaluating your printing needs. 7.1.1.1. Function Evaluating your organizational needs and how a printer services those needs is the essential criteria in determining the right type of printer for your environment. The most important question to ask is " What do we need to print? " Since there are specialized printers for text, images, or any variation thereof, you should be certain that you procure the right tool for your purposes. For example, if your requirements call for high-quality color images on professional-grade glossy paper, it is recommended you use a dye-sublimation or thermal wax transfer color printer instead of a laser or impact printer. Conversely, laser or inkjet printers are well-suited for printing rough drafts or documents intended for internal distribution (such high-volume printers are usually called workgroup printers). Determining the needs of the everyday user allows administrators to determine the right printer for the job. Other factors to consider are features such as duplexing -- the ability to print on both sides of a piece of paper. Traditionally, printers could only print on one side of the page (called simplex printing). Most lower-end printer models today do not have duplexing by default (they may, however, be capable of a manual duplexing method that requires the user to flip the paper themselves). Some models offer add-on hardware for duplexing; such add-ons can drive one-time costs up considerably. However, duplex printing may reduce costs over time by reducing the amount of paper used to print documents, thus reducing the cost of consumables -- primarily paper. Another factor to consider is paper size. Most printers are capable of handling the more common paper sizes: letter -- (8 1/2" x 11") A4 -- (210mm x 297mm) JIS B5 -- (182mm x 257mm) legal -- (8 1/2" x 14") If certain departments (such as marketing or design) have specialized needs such as creating posters or banners, there are large-format printers capable of using A3 (297mm x 420mm) or tabloid (11" x 17") paper sizes. In addition, there are printers capable of even larger sizes, although these are often only used for specialized purposes, such as printing blueprints. Additionally, high-end features such as network modules for workgroup and remote site printing should also be considered during evaluation. 7.1.1.2. Cost Cost is another factor to consider when evaluating printers. However, determining the one-time cost associated with the purchase of the printer itself is not sufficient. There are other costs to consider, such as consumables, parts and maintenance, and printer add-ons. As the name implies, consumables is a general term used to describe the material used up during the printing process. Consumables primarily take the form of media and ink . The media is the material on which the text or image is printed. The choice of media is heavily dependent on the type of information being printed. For example, creating an accurate print of a digital image requires a special glossy paper that can withstand prolonged exposure to natural or artificial lighting, as well as ensure accuracy of color reproduction; these qualities are known as color fastness . For archival-quality documents that require durability and a professional level of legibility (such as contracts, resumes, and permanent records), a matte (or non-glossy) paper should be used. The stock (or thickness) of paper is also important, as some printers have a paper path that is not straight. The use of paper that is too thin or too thick can result in jams. Some printers can also print on transparencies , allowing the information to be projected on a screen during presentations. Specialized media such as those noted here can affect the cost of consumables, and should be taken into consideration when evaluating printing needs. Ink is a generalized term, as not all printers use liquid inks. For example, laser printers use a powder known as toner , while impact printers use ribbons saturated with ink. There are specialized printers that heat the ink during the printing process, while others spray small droplets of ink onto the media. Ink replacement costs vary widely and depend on whether the container holding the ink can be recharged (refilled) or if it requires a complete replacement of the ink cartridge .

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