It ’s almost axiomatic that thriving industriousness create their own jargon — and nowhere is this truer than in the existence of computer , where vendor borrow , adjust , and coin words on the face of it on a everyday foundation . At some point , however , all the adoption and pun create confusion — peculiarly for the hoi polloi who want tousea engineering .
computing machine printer vender have borrowed much of their unique dialect of acronyms , nicknames , and terms from traditional printing , but often put a different spin on the terminology . Apart from their marketing purpose , many of the predominant damage on a printer ’s specification page are utile clues that can serve you choose the best gadget for your needs — if you’re able to realize them . Here ’s a agile summing up of terms and concepts you need to know .
Resolution or DPI
Printers work by depositing midget amounts of a color ( ink , toner , dye ) on a open like paper ; each of these building block of vividness is call adot — and the first matter that eld of ads and marketing have teach us to look for on a printing machine ’s spec page is its DPI or battery-acid - per - column inch . This routine tells us how many battery-acid the pressman is capable of fitting in a give space and , since the dot are the building block of text and pictures , a higher number is considered effective .
You may marvel why printers have a much higher DPI than computing machine screens , where mark command originate : a typical inkjet these days easily exceeds 1,000 DPI , while the iPhone 4 ’s Retina exhibit — probably the most pixel - thick screen uncommitted to consumers — hardly makes it to 300 picture element per inch ( PPI generally relate to monitor resolution , while DPI analogously relate to print resolving power ) . The reason is that most printing machine can regurgitate a very little number of colors — for instance , a distinctive inkjet with four ink cartridges can produce a upper limit of 16 colors for each dot ( known as color depth ) , while a unmarried pixel on the screen is commonly capable of displaying several million unlike hue .
On paper , therefore , limited techniques such as half - toning or dithering are used to print adjacent dots in a specific normal ; because they are so tiny , once the brain comprehend them , they are mix in into the intended color , thus giving the pressman a wider - range gamut than it is potential with just its four basic ink hues .
A matter of color
When you compare printers , you must think not only their ability to publish dot in close propinquity , but also how many single colouring they can print in any give dot location . laser and the less - expensive inkjets have only four ink reservoirs ; at a given DPI , therefore , their semblance depth will be lower than the more expensive inkjet modeling that sport five , six , or even seven different ink colour . dyestuff - sublimation printers offer the good character for a pass on DPI because it can merge inks on the paper and thus provide a nearly boundless routine of colors .
Keep in mind that the final print quality depends on a lot more than the DPI rating . Inkjets , for example , literally hit liquid ink at your page ; look on the paper , the ink could be absorbed and shed blood , causing blurry edges . A optical maser printer , by contrast , will ordinarily have better bound contrast because it deposits toner on the varlet and then melt it into lieu .
Marketing gimmicks have also muddled the very concept of DPI . For exemplar , you may see some pressman manufacturer call that its product have “ optimise ” DPI ratings obtained through a change of proficiency , such as passing the photographic print headspring over the same placement multiple time or printing dit of vary shapes . These usually result in a higher maximum print quality , but often at the expense of speed and ink using up .
Finally , a straightaway look at your local electronic computer retail merchant or on-line store will expose that many printer have not one , buttworesolution ratings — for example , 2400 x 1200 DPI . The first phone number indicates the horizontal resolution , while the 2nd gives you its vertical twin . This difference is commonly due to the printing head configuration and the underlying newspaper transport mechanic , which are designed to provide the correct via media of speed and tone to stay within the printing machine ’s terminal price chain . In pragmatic terms , your printer ’s driver will adjust the final output quality and you will not see a large difference .
Speed
Print speed is normally expressed as Page per minute ( PPM ) . While this seems aboveboard , unfortunately , there ’s no universal definition of what a “ Sir Frederick Handley Page ” really is .
Most printer manufacturers tell you that their speed tests are base on a alphabetic character - size page with an ink coverage of five percent . The job is thatwherethat ink is site can dramatically affect the amphetamine of some type of printers , while the complexness of the image and school text print could slow down some others .
For model , inkjet printers have a printing head that move horizontally — thus , if the superman that make up the image printed are spread all over the page , the print capitulum will have to move around a lot more than if the dots were concentrated in a single positioning , resulting in a lower f number . Laser printers , on the other hand , need to write a physical delegacy of an intact page before they can print it ; if the commands required to compile a Sir Frederick Handley Page are particularly complex , it will take more time to output .
Different printing modes also result in different PPM ratings . maker typically provide value for color and grayscale , especially in “ multi - pass ” laser printing machine , where the composition must take a longer path to print pages of the former type . The dead on target variances , however , are often much subtler than that . you’re able to bet that printing in photo quality will be slower than printing in draft style — and that the PPM branded on the printer ’s boxwood is unlikely to express the amphetamine of the former .
Therefore , it ’s good to take the published PPM as an indication of theaveragespeed of a printing machine — the higher , the better .
Durability
Another rating that you ’re likely to notice in the context of printer performance is theduty bicycle . This figure expresses the bit of pages of output per month that a printer was designed to do by — typically , the manufacturer will start with this routine as a finish and make a telephone number of design decision to fulfil it . These include the turn and capability of the paper tray , the efficiency of the printer ’s cooling organisation , the quality and resiliency of its electromechanical element , and so on .
Depending on its think usage , therefore , a printing machine ’s responsibility oscillation can vary considerably . Less expensive consumer inkjets could have a cycle of 3,000 pages per calendar month , while professional lasers can go past 100,000 Sir Frederick Handley Page per month . When pick a printing machine , this telephone number is only relevant in give you a clue as to what kind of body of work it was design to do by . Keep the duty cps in mind as you evaluate other feature like ink price and relative frequency of refilling , the price of maintenance kits , and so on .
Memory
Much like a computer demand graphical memory to expose image on a screen , a laser pressman postulate memory board to understand the commands that make up a Thomas Nelson Page and make its representation so that it can print .
This make RAM a very important — sometimes decisive — resource . Insufficient retentiveness could ensue in the printer simply refusing to output a complex page , since it simply can not draw up it . Conversely , more computer memory will activate the printer to hold more information and speed up up the printing process . By the same token , colouring material printers typically need more memory than their disgraceful - and - white counterparts , since each dot to be printed incorporate at least four times as much information .
Note that the amount of printing machine memory is tied to the sizing of a particular page , andnotof an integral papers . Therefore , a printer with 32 MB of memory may be perfectly equal to of printing a 100 M document , as long as none of its page expect more than 32 MB to be .
In practical terms , making the right selection is as much fine art as science , and manufacturer have become quite good at calibrating a printer ’s retentiveness alongside its responsibility cycle : users who need to impress more Sir Frederick Handley Page are also more likely to print complex written document and , therefore , require more RAM , or so the abstract thought goes . Whether or not that is the caseful take down that the RAM in most printers can be upgraded — although often at a much usurious monetary value than figurer .
Printing language
Printers come in many miscellany , but they all share a common trouble : they postulate to mouth to a computing machine , and this requires some agreed - upon communications protocol . In printer idiom , this protocol is called a Page Definition Language ( PDL ) .
The two most popular pdl arePostScript , which was modernize by Adobe Systems , and Page Command Language , orPCL , which was developed by Hewlett - Packard . The latter was designed as a wide-eyed but flexible protocol whose chief end was to agitate as much of the work to the information processing system as potential in an feat to keep pressman simple and inexpensive . Adobe ’s answer , on the other hand , is a much more complex , but also more powerful , spoken language designed primarily for printing professionals .
In the past tense , this meant that PostScript printer were importantly more expensive than their PCL opposite number , produced better and more ordered solvent , and were more widely affirm ( both OS X and Linux bear Postscript natively ) . PCL printer were often cheaper , but originally design to work with Windows and did not always include drivers for other operating systems . More of late , however , this note has become less relevant . The cost of PostScript printers has decreased significantly , and almost every PCL - compatible printer now comes with OS X driver .
These day , the option of one poundal over the other is mostly relevant to industry professionals — from a consumer linear perspective , it ’s more important to ensure that OS X has the right drivers for the printer you want to grease one’s palms and allow the operating system take care of the eternal sleep .
There are , however , some communications protocol - related options that youshouldkeep in mind when shopping . The first isDirect PDF Printing , which allows a PostScript printing machine to perform all the steps required to print a PDF document without any assistance from the computer . This allay meshing load and computation requirements , which can be quite onerous for complex documents .
The 2d engineering science to keep an eye on is Airprint , which will allow iOS devices equipped with translation 4.2 of Apple ’s mobile operating system to impress directly to compatible printer without having to unite through a computing machine . So far , only Hewlett Packard has announced build - in support for Airprint in itsePrintlineup , but it stands to reason that other manufacturers will pursue case , or risk leaving a potentially remunerative market in the handwriting of a rival .
Bottom line
As you could see , printer terminology is sometimes hard to understand , with complex concepts often lurking behind the simple numbers that you find printed on boxes and manuals . With a flake of enquiry , however , you could use the information that manufacturers bring home the bacon to make a more informed conclusion the next meter you ’re shopping for a pressman .
[ Marco Tabini is a Web specializer ground in Toronto . ]
