Printer steganography is a type of steganography – "hiding data within data" – produced by color printers, including Brother, Canon, Dell, Epson, HP, IBM, Konica Minolta, Kyocera, Lanier, Lexmark, Ricoh, Toshiba and Xerox brand color laser printers, where tiny yellow dots are added to each page. The dots are barely visible and contain encoded printer serial numbers, as well as date and time stamps.
In a typical drum printer design, a fixed font character set is engraved onto the periphery of a number of print wheels, the number matching the number of columns (letters in a line) the printer could print. The wheels, joined to form a large drum (cylinder), spin at high speed and paper and an inked ribbon is stepped (moved) past the print position. As the desired character for each column passes the print position, a hammer strikes the paper from the rear and presses the paper against the ribbon and the drum, causing the desired character to be recorded on the continuous paper. Because the drum carrying the letterforms (characters) remains in constant motion, the strike-and-retreat action of the hammers had to be very fast. Typically, they were driven by voice coils mounted on the moving part of the hammer.
Band printers are a variation of chain printers, where a thin steel band is used instead of a chain, with the characters embossed or etched onto the band. Again, a selection of different bands are generally available with a different mix of characters so a character set best matched to the characters commonly printed can be chosen. Dataproducts was a well known manufacturer of band printers, with their B300, B600, and B1000 range, the model number representing the lines per minute rate of the printer. (The B300 is effectively a B600 with only half the number of hammers—one per two character positions. The hammer bank moves back and forth one character position, requiring two goes to print all characters on each line.)
Chain printers (also known as train printers) place the type on a horizontally-moving chain or on a track. As with the drum printer, as the correct character passes by each column, a hammer is fired from behind the paper. Compared to drum printers, chain printers have the advantage that the type chain can usually be changed by the operator. A further advantage is that vertical registration of characters in a line is much improved over drum printers, which need extremely precise hammer timing to achieve a reasonably straight line of print. By selecting chains that have a smaller character set (for example, just numbers and a few punctuation marks), the printer can print much faster than if the chain contains the entire upper- and lower-case alphabet, numbers, and all special symbols. This is because, with many more instances of the numbers appearing in the chain, the time spent waiting for the correct character to "pass by" is greatly reduced. Common letters and symbols appear more often on the chain, according to the frequency analysis of the likely input. It is also possible to play primitive tunes on these printers by timing the nonsense of the printout to the sequence on the chain, a rather primitive piano. IBM was probably the best-known chain printer manufacturer and the IBM 1403 is probably the most famous example of a chain printer.
Today, most printers accept one or more page description languages (PDLs). Laser printers with greater processing power frequently offer support for variants of Hewlett-Packard's Printer Command Language (PCL), PostScript or XML Paper Specification. Most inkjet devices support manufacturer proprietary PDLs such as ESC/P. The diversity in mobile platforms have led to various standardization efforts around device PDLs such as the Printer Working Group (PWG's) PWG Raster.
Most printers other than line printers accept control characters or unique character sequences to control various printer functions. These may range from shifting from lower to upper case or from black to red ribbon on typewriter printers to switching fonts and changing character sizes and colors on raster printers. Early printer controls were not standardized, with each manufacturer's equipment having its own set. The IBM Personal Printer Data Stream (PPDS) became a commonly used command set for dot-matrix printers.
The communication between the Game Boy and the Game Boy Printer is via a simple serial link. Serial clock (provided by the Game Boy for the printer), serial data output (from Game Boy to printer) as well as serial data input (to Game Boy from printer). The Game Boy sends a packet to the printer, to which the printer responds with an acknowledgement as well as a status code.
A roll of the American Game Boy Printer paper came in red, blue, yellow and white, with an adhesive backing. It had a width of 38mm and a diameter of 30mm, with a 12mm cardboard spindle in the centre. A typical roll had 390–400 cm of length. When a picture printed from the Game Boy Camera, it would print with a .5 cm margin above and below the picture and print the picture at a 2.3 cm height. This would give the total of 3.3 cm height per picture. The Game Boy Printer paper refills boasted up to 180 pictures per roll. With the math, the typical roll could only take 118 pictures. The paper is now hard to find; it could be substituted with a 1.5 in thermal paper without repercussions on the printer.
There is some scholarly disagreement about whether or not Crowley actually operated or managed a press that he owned or leased. On the one hand, Olga Illston’s "A Literary and Bibliographical Study of Robert Crowley" (M.A. Thesis, London University, 1953) is the basis for the Revised Short Title Catalogue (STC or RSTC) and current ESTC identification of Richard Grafton, the King's printer, as the printer of many of Crowley's books under Edward VI. Illston demonstrates that the initial blocks used in Crowley's books between 1549 and 1551 belonged to Grafton, and she notes the frequent use of the same type in Grafton and Crowley imprints. This led to the STC revisers and other scholars, most notably John N. King, to conclude that Crowley never had his own press, but was only a bookseller. The revised STC generally follows Illston, although Illston attributed the printing of Crowley's Psalter to Richard Jugge with assistance from Grafton; the revised STC, King, and other sources identify Stephen Mierdman as its printer.
In the past, particularly noisy printer such as dot matrix and daisy wheel designs were often housed in soundproofed boxes or cabinets, and the same technique can be used with modern printers to reduce their perceived noise. Another solution is to network the printer, and locate it physically away from the immediate work area.
The printer used to make the rifle was a Stratasys Dimension 1200es printer costing $10,000 as of August 2013. It was made using ABS plastic.
The line printers have 12 sensors to recognize 12 independent positions on the carriage control tape. Each position is called a channel, numbered from 1 to 12. If a hole is punched in a channel, then this hole marked a position on the page that the printer can 'jump to' quickly by advancing until the hole is sensed by the corresponding channel sensor. This is called skip to channel number n.
In Eld's historical era, most stationers concentrated on either printing or bookselling; and most publishing was done by the booksellers, who commissioned the printers to print their works. Eld was primarily a printer during his career, working on specific projects for specific booksellers.
The calculator can be programmed to request input from the user, and output results of calculations to the printer. Alphanumeric text (64 characters total, including space, 0-9, A-Z and 25 punctuation and mathematical symbols) can be output as well as numbers. A limited ability to plot graphs is provided. The printer is also valuable for program development because it can produce a hard copy of the calculator's program including the alphanumeric mnemonics instead of just the numeric codes normally visible on the display, as well as a dump of the data registers, a trace of the program's execution and other information about the program.
In the early model PC-100A, a switch inside the battery charger compartment allows use with the earlier SR-52 and SR-56 calculators as well as the TI-58/59 series. In addition, it also works with non-programmable TI machines of the era such as the SR-50A. (Remove the battery pack of a TI calculator and look for the row of printer interface pads on the circuit board below the battery terminals.)
The engine was printed with a GPI Prototype and Manufacturing Services printer using a technique called Direct metal laser sintering (DMLS). In the process of printing, a powder of the chromium-cobalt alloy is spread in a thin layer. Then computer-controlled laser fuses the powders into a cross section of the engine component. The machine then spreads a second layer of powder and the process continuously repeats until each component is complete. Any excess powder is removed as are temporary supports that were printed to hold the components together during printing process. Finally it is hardened, polished and assembled.
In his two-decade career, Eld printed a wide variety of works; when the printer is identified on title pages only with initials, researchers have used Eld's characteristic title-page device, "two volutes with foliage," for supporting evidence. He is the "G. E." who printed William Camden's Remains of a Greater Work (1605) for Simon Waterson, John Selden's The Duello (1610) for John Helme, and Peter Gosselin's The State Mysteries of the Jesuits (1623) for Nicholas Bourne.
With John Macock he styled himself a printer to Parliament in 1659 and 1660. After the Restoration he became a successful commercial printer, in particular with titles by Nicholas Culpeper from the backlist of Peter Cole who committed suicide in 1665. He had a specific exemption from the 1662 Act regulating publishers.
As a printer Stansby worked for many of the booksellers of his era; he also worked repeatedly for several stationers over the years. For John Smethwick, Stansby printed several editions of the collected Poems of Michael Drayton (1609–30), plus several of the later editions of prose works by Robert Greene, like Menaphon (1616, 1631) and Never Too Late (1621). Stansby printed collections of the sermons of Barten Holyday for Nathaniel Butter. (He also printed Holyday's only play, Technogamia, for John Parker.)
The ICC profile for a printer is created by comparing a test print result using a photometer with the original reference file. The testchart contains known CMYK colors, whose offsets to their actual L*a*b* colors scanned by the photometer are resulting in an ICC profile. Another possibility to ICC profile a printer is to use a calibrated scanner as the measuring device for the printed CMYK testchart instead of a photometer. A calibration profile is necessary for each printer/paper/ink combination.