Near letter-quality (NLQ) printing is a process where

dot matrix printers A dot matrix printer is an impact printer that prints using a fixed number of pins or wires. Typically the pins or wires are arranged in one or several vertical columns. The pins strike an ink-coated ribbon and force contact between the ribbon ...

produce high-quality text by using multiple passes to produce higher dot density. The tradeoff for the improved print quality is reduced printing speed. Software can also be used to produce this effect. The term was coined in the 1980s to distinguish NLQ printing from true letter-quality printing, as produced by a printer based on traditional typewriter technology such as a

daisy wheel Daisy wheel printing is an impact printing technology invented in 1970 by Andrew Gabor at Diablo Data Systems. It uses interchangeable pre-formed type elements, each with typically 96 glyphs, to generate high-quality output comparable to pre ...

, or by a

laser printer Laser printing is an electrostatic digital printing process. It produces high-quality text and graphics (and moderate-quality photographs) by repeatedly passing a laser beam back and forth over a negatively-charged cylinder called a "drum" to d ...

. In 1985 The New York Times described the marketing of

printers Printer may refer to: Technology * Printer (publishing), a person or a company * Printer (computing), a hardware device * Optical printer for motion picture films People * Nariman Printer ( fl. c. 1940), Indian journalist and activist * Jame ...

with the terms "''near letter-quality'', or N.L.Q." as "just a neat little bit of hype", but acknowledged that they "really show their stuff in the area of fonts, print enhancements and graphics".

Technology overview

''Near letter-quality'' is a form of impact

dot matrix printing Dot matrix printing, sometimes called impact matrix printing, is a computer printing process in which ink is applied to a surface using a relatively low-resolution dot matrix for layout. Dot matrix printers typically use a print head that moves ...

. What The New York Times called "

dot-matrix A dot matrix is a 2-dimensional patterned array, used to represent characters, symbols and images. Most types of modern technology use dot matrices for display of information, including mobile phones, televisions, and printers. The system is al ...

impact

printing Printing is a process for mass reproducing text and images using a master form or template. The earliest non-paper products involving printing include cylinder seals and objects such as the Cyrus Cylinder and the Cylinders of Nabonidus. The ea ...

", was deemed almost good enough to be used in a business letter Reviews in the later 1980s ranged from "good but not great""reminded me that I was reading text printed by a printer rather than by a typewriter. Output from both draft and NLQ modes falls into the category of good but not great. In NLQ, the edges of the letters are slightly ragged." to "endowed with a simulated typewriter-like quality". By using multiple passes of the carriage, and higher dot density, the printer could increase the effective resolution."... it is accomplished by shifting the print head ever so slightly after each character and then reprinting it. The double strike produced in this fashion yields a higher dot density." For example, the Epson FX-86 could achieve a theoretical ''addressable'' dot-grid of 240 by 216 dots/inch using a print head with a vertical dot density of only 72 dots/inch, by making multiple passes of the print head for each line. For 240 by 144 dots/inch, the print head would make one pass, printing 240 by 72 dots/inch, then the printer would advance the paper by half of the vertical dot pitch (1/144 inch), then the print head would make a second pass. For 240 by 216 dots/inch, the print head would make three passes with smaller paper movement (1/3 vertical dot pitch, or 1/216 inch) between the passes. To cut hardware costs, some manufacturers merely used a ''double strike'' (doubly printing each line) to increase the printed text's boldness, resulting in bolder but still jagged text. In all cases, NLQ mode incurred a severe speed penalty. Because of the slow speed of NLQ printing, all NLQ printers have at least one "draft mode", in which the same

font In metal typesetting, a font is a particular size, weight and style of a typeface. Each font is a matched set of type, with a piece (a "sort") for each glyph. A typeface consists of a range of such fonts that shared an overall design. In mod ...

s are used, but with only one pass of the print head per line. This produces lower-resolution printing, but at higher speed. Expensive NLQ printers had multiple fonts built-in, and some had a slot where a font cartridge could be inserted to add more fonts. Printer utility software could be used to print with multiple fonts on less-expensive printers. Not all of these utilities worked with all printers and applications, however.

References

{{reflist Impact matrix printers History of computing hardware