and the various types of ink and paper

 

Printer - a device that prints text or illustrations on paper by laying down ink on the surface. There are many different types of printers. In terms of the technology utilized, printers fall into the following categories: 

Yesterday's Printers

 

Today's Printers

Printers are also classified by the following characteristics: 

Quality of Type: The output produced by printers is said to be either letter quality (as good as a typewriter),
near letter quality, or draft quality.  Draft quality is used to save on ink, for printing out rough drafts.  Color printers are notorious for running out of ink quickly, and the ink cartridges are pricey - so Draft quality is useful and economical. 

Impact or Non-Impact: Impact printers include all printers that work by striking an ink ribbon. Daisy-wheel,
dot-matrix, and line printers are impact printers. Non-impact printers include laser printers and ink-jet
printers. The important difference between impact and non-impact printers is that impact printers are much
noisier. 

Graphics: Some printers (daisy-wheel and line printers) can print only text. However, all modern printers can print both text and graphics. Graphics are sent to the printer as "bit-mapped", which is essentially a rectangle of dots, or "bits" - each bit sent will contain the color information, and brightness

Fonts : Some printers, notably dot-matrix printers, are limited to one or a few fonts. In contrast, laser and
ink-jet printers are capable of printing an almost unlimited variety of fonts. Daisy-wheel printers can also print
different fonts, but you need to change the daisy wheel, making it difficult to mix fonts in the same document.  The printer itself can store fonts in it's memory, which results in faster printing.  If the printer does not have the font being printed, then the PC will send the information as bit-mapped graphics, which requires much more data to be delivered, and is therefore slower.  

 

Laser or Ink-Jet ??

This is one area where I must advise you to spend a few extra dollars.  The majority of users have a color Ink-Jet printer, typically one that came with their PC.  These are fine for color.  Unfortunately, Ink-Jets use small, expensive cartridges of liquid ink (one tri-color, and one black cartridge), and run out of ink very quickly.   In addition, their text for B&W prints is not very good.  Nevertheless, you need one of these, because they make beautiful color prints, and there will definitely be times when you need to print in color (banners, flyers, invitations, important presentations, etc.).

The bulk of your printing will be in Black and White.  Previously priced in the stratosphere, B&W laser printers have come down to the reasonable range, and they are well worth it.  Since the bulk of your printing will be Black and White, get a B&W laser printer.  In addition. the B&W laser printer uses large reservoirs of "toner", which is a black powder - and these last forever.  You will probably be able to print regularly for 6 months to a year without having to change tone cartridges.

The difference between the cartridge sizes is amazing, as shown here :

Laser Toner Cartridge and Inkjet Tricolor & Black Ink Cartridges

My recommendation is simple for the Ink-Jet color printer  .  .  .  the "HP DeskJet 970Cse".  I have dealt with hundreds of color printers, and nothing comes close.  This printer is very fast, very quiet, and stunning.

My recommendation for a B&W laser is less objective.  I have an HP 5L, which as I mentioned, has a poor feed mechanism, and takes doubles, triples, and even 10 sheets at a time occasionally.  I have heard that the Minolta QMS Page Pro is an excellent printer, and at around 250 bucks, it's a steal.

Now, here is the best part (if you have a USB port, that is).  Since most PC's have only one parallel port (the printer port), to use two printers, you would have to buy a Printer sharing box, and these boxes can be unreliable, although if you have no USB port, you will want to get one of these devices.  All modern PC's come with two USB ports, and the HP 970Cse has a USB port as well.  You will need to buy a USB cable - but then you can plug one printer into your USB port and the other into your parallel port.

Laser Printers

A type of printer that utilizes a laser beam to produce an image on a drum. The light of the laser alters the electrical charge on the drum wherever it hits. The drum is then rolled through a reservoir of toner, which is picked up by the charged portions of the drum. Finally, the toner is transferred to the paper through a combination of heat and pressure.  This is also the way copy machines work. 

One of the chief characteristics of laser printers is their resolution -- how many dots per inch (dpi) they lay down. The available resolutions range from 300 dpi at the low end to 1,200 dpi at the high end. By comparison, offset printing usually prints at 1,200 or 2,400 dpi. Some laser printers achieve higher resolutions with special techniques known generally as resolution enhancement. 

Most laser printers come with a basic set of fonts, called internal or resident fonts, but you can add additional fonts in one of two ways: 

font cartridges : Laser printers have slots in which you can insert font cartridges, ROM boards on which fonts have been recorded. The advantage of font cartridges is that they use none of the printer's memory

soft fonts : All laser printers come with a certain amount of RAM memory, and you can usually increase the amount of memory by adding memory boards in the printer's expansion slots. You can then copy fonts from a disk to the printer's RAM. This is called downloading fonts. A font that has been downloaded is often referred to as a soft font, to distinguish it from the hard fonts available on font cartridges. The more RAM a printer has, the more fonts that can be downloaded at one time. 

In addition to text, laser printers are very adept at printing graphics. However, you need significant amounts of memory in the printer to print high-resolution graphics. To print a full-page graphic at 300 dpi, for example, you need at least 1 MB (megabyte) of printer RAM. For a 600-dpi graphic, you need at least 4 MB RAM.  Because laser printers are nonimpact printers, they are much quieter than dot-matrix or daisy-wheel printers. They are also relatively fast, although not as fast as some dot-matrix printers. The speed of laser printers ranges from about 4 to 20 pages of text per minute (ppm). A typical rate of 6 ppm is equivalent to about 40 characters per second (cps).  

Laser printers are controlled through page description languages (PDLs). There are two de facto standards for
PDLs: 

PCL (Printer Control Language) : Hewlett-Packard (HP) was one of the pioneers of laser printers and has developed a Printer Control Language (PCL) to control output. There are several versions of PCL, so a printer may be compatible with one but not another. In addition, many printers that claim compatibility cannot accept HP font cartridges.  

PostScript : This is the de facto standard for Apple Macintosh printers and for all desktop publishing systems.  Most software can print using either of these PDLs. PostScript tends to be a bit more expensive, but it has some features that PCL lacks and it is the standard for desktop publishing. Some printers support both PCL and PostScript. 

PCL is now by far the most common page description language.  It is also very useful for home networks, where a printer is attached to one PC and the others PC's must send their print jobs through the main PC.  The remote PC's can use PCL, since the printer is not connected directly to their parallel port.  Post Script has faded quite a bit, and is becoming a bit rare.

The dpi Setting

Most laser printers have an adjustable setting for dpi (dots per inch).  The setting can be changed in the dialog box that pops up when you click File/Print within an application - so it is not a hard setting, rather, it is a signal sent to the printer by your PC.  It seems a bit surprising that this is adjustable - why wouldn't you want the finest quality on all your printouts?  The only reason I can come up with is speed, but at least on my HP 5K printer (B&W), the speed seems the same no matter what I set the dpi to.

The connection between the dpi of the image within the application, the printer dpi, and the pixel size of the image is covered in great detail in the Monitor section.  It is very, very confusing !!  Let it suffice to say, that the printer dpi setting of the image within Abobe Photoshop (I use that as an example since it is the premiere imaging software of the world) is not the same as the printer dpi setting you use in the Print Dialog box just prior to sending the print job.

I used the same small color image example that I used in the monitor section - with color components removed :

 

Within Photoshop, you can go to Image/Image Size, to see the print resolution ppi setting (Not the Same as the Printers dpi Resolution !!! )

For the following print examples, I left the image size section where it says "Print Size" alone - at 72 ppi (pixels per inch).  Realize that the application will send the printer information at 72 pixels per inch.  Therefore, the detail cannot be greater than 72 pixels per inch.  However, I can still print at 600 dot per inch (the max of my printer), and it will lay down 600 dots per inch !!!  But what happens - is that the dots will repeat.  The ratio if you use one direction such as width is 600 dots for every 75 pixels, or 600/75 = 8.  So, there are 8 printer dots to fill the width of one pixel - and that is only in one direction.  The total number of dots per pixel is width x height = 8 x 8 = 64 dots per pixel.  One pixel printed on the paper, magnified, would ideally look like this (actually it would not have the white lines - which are there simply to show you where the dots begin and end) :

With that in mind, I sent the tiny gray-scale image to the printer at each of the dpi settings that my printer supports, and you can see, that regardless of the constant 72 ppi print setting in Photoshop, the results were quite different (these are actual close-up snapshots of the printouts) :

 

The enlarged 32x22 original image from Photoshop

The printouts  .  .  .
(info under each pic is ppi sent to printer, and dpi actually printed)

               

72 ppi,  75 dpi                                                    72 ppi, 150 dpi

 

               

72 ppi,  300 dpi                                                    72 ppi, 600 dpi

Note that the 75 dpi printout was basically a disaster.  At first I assumed that the problem was that the printer received a 72 ppii image and had to interpolate it to 75 dpi.  So I changed the ppi within Photoshop to 75 ppi and reprinted it at 75 dpi - the results were basically the same.  The problem is that the printer must create shades of gray which requires interpolation and half toning.  You need enough dots to halftone, and the tiny image did not give the printer enough dots at 75 dpi to perform quality half toning.  To test this theory, I used the same size image but filled the little areas in with either white or black, and printed at 75 dpi.  This meant that there was no half toning to be done for grayscale shades . . . and as expected, the printout cleared up :

 

Inkjet Printers

Although inkjets were available in the 1980s, it was only in the 1990s that prices dropped enough to bring the technology to the high street. Canon claims to have invented what it terms 'bubble jet' technology in 1977, when a researcher accidentally touched an ink-filled syringe with a hot soldering iron. The heat forced a drop of ink out of the needle and so began the development of a new printing method.

    BubbleJet is Inkjet - don't let Canon fool you.

Inkjets are generally cheaper to buy than lasers, but they are more difficult to maintain. Cartridges need to be changed frequently, and they are rather expensive and small.  Nevertheless,  inkjet printing has become immensely popular. 

Operation - inkjet printing, like laser printing, is a non-impact method. Ink is emitted from nozzles as they pass over a variety of possible media, and the operation of an inkjet printer is easy to visualise: liquid ink in various colors being squirted at the paper to build up an image. A print head scans the page in horizontal strips, using a motor assembly to move it from left to right and back, as another motor assembly rolls the paper in vertical steps. A strip of the image is printed, then the paper moves on, ready for the next strip. To speed things up, the print head doesn’t print just a single row of pixels in each pass, but a vertical row of pixels at a time.

On ordinary inkjets, the print head takes about half a second to print a strip across a page. Since A4 paper is about 8.5in wide and inkjets operate at a minimum of 300dpi, this means there are at least 2,475 dots across the page. The print head has, therefore, about 1/5000th of a second to respond as to whether or not a dot needs printing. In the future, fabrication advances will allow bigger print-heads with more nozzles firing at faster frequencies, delivering native resolutions of up to 1200dpi and print speeds approaching those of current color laser printers (3 to 4ppm in color, 12 to 14ppm in monochrome).

There are several types of inkjet technology but the most common is ‘drop on demand’ (DOD). This works by squirting small droplets of ink onto paper, through tiny nozzles: like turning a hosepipe on and off 5,000 times a second. The amount of ink propelled onto the page is determined by the driver software that dictates which nozzles shoot droplets, and when.

The nozzles used in inkjet printers are hair fine and on early models they became easily clogged. On modern inkjet printers this is rarely a problem, but changing cartridges can still be messy on some machines. Another problem with inkjet technology is a tendency for the ink to smudge immediately after printing, but this, too, has improved drastically during the past few years with the development of new ink compositions.

Thermal Technology - Most inkjets use thermal technology, whereby heat is used to fire ink onto the paper. There are three main stages with this method. The squirt is initiated by heating the ink to create a bubble until the pressure forces it to burst and hit the paper. The bubble then collapses as the element cools, and the resulting vacuum draws ink from the reservoir to replace the ink that was ejected. This is the method favored by Canon and Hewlett-Packard.  The difference is - Canon tried to trumpet to the world that they have this special technology called "Bubble-Jet", which all the other companies use the same thing, as just call it, appropriately - Inkjet.

Thermal technology imposes certain limitations on the printing process in that whatever type of ink is used, it must be resistant to heat because the firing process is heat-based. The use of heat in thermal printers creates a need for a cooling process as well, which levies a small time overhead on the printing process.

Tiny heating elements are used to eject ink droplets from the print-head's nozzles. Today's thermal inkjets have print heads containing between 300 and 600 nozzles in total, each about the diameter of a human hair (approx. 70 microns). These deliver drop volumes of around 8 - 10 picolitres (a picolitre is a million millionth of a litre), and dot sizes of between 50 and 60 microns in diameter. Nozzle density, corresponding to the printer's native resolution, varies between 300 and 600dpi, with enhanced resolutions of 1200dpi increasingly available. Print speed is chiefly a function of the frequency with which the nozzles can be made to fire ink drops and the width of the swath printed by the print-head. Typically this is around 12MHz and half an inch respectively, giving print speeds of between 4 to 8ppm (pages per minute) for monochrome text and 2 to 4ppm for color text and graphics. 

Ink and Colors

Printers use "subtractive" colors - CMY.

*** to understand color - see our "Color Theory" page

Today the vast majority of home users own a DeskJet type printer, whuch uses tint nozzles to literally spray ink onto the paper in extremely fine streams.  A typical, 3-color ink cartridge is shown below.  Many people think printers use the same 3 colors that TV screens and monitors use - Red, Green, and Blue.  However almost all printers use the opposite 3 primary colors Yellow, Magenta, and Cyan.

Color is a very complex topic.  We need to at least go over the theory of the "color wheel", "primary colors", and "complementary colors" to be able to explain printer inks.  "Primary Colors are described differently depending on whether it is a additive color (mixing light) or a subtractive color (mixing inks).

Additive ColorColor wheels show how visible colors are related. Primary, secondary, and intermediate colors are organized on a circular chart. Color wheels help artists remember how to mix and think about pigments.

Color wheels are based on color theory, which is based on the physics of light. There are two common types of color: additive color and subtractive color.

 

 

RGB (Red, Green, Blue) and CMYK (Cyan, Magenta, Yellow, Black) are other common color models. CRT monitors use the former, creating color by causing red, green, and blue phosphors to glow; this system is called additive color. Mixing different amounts of each of the red, green or blue, creates different colors, and each can be measured from 0 to 255. If all red, green and blue are set to 0, the color is black, is all are set to 255, the color is white.

The human eye can distinguish around a million colors, the precise number depending on the individual observer and viewing conditions. Color devices create colors in different ways, resulting in different color gamuts.

Color can be described conceptually by a three-dimensional HSB model:

Printer-Monitor Color Matching

The desired concept is true WSIWYG (What You See Is What You Get), where the printed image looks exactly like the image on the monitor.

Monitors and printers do this slightly differently however because monitors are light sources, whereas the output from printers reflects light. So, monitors mix the light from phosphors made of the primary additive colors: red, green and blue (RGB), while printers use inks made of the primary subtractive colors: cyan, magenta and yellow (CMY). White light is absorbed by the colored inks, reflecting the desired color. In each case, the basic primary colors are dithered to form the entire spectrum. Dithering breaks a color pixel into an array of dots so that each dot is made up of one of the basic colors or left blank.

The reproduction of color from the monitor to the printer output is also a major area of research known as color-matching. Colors vary from monitor to monitor and the colors on the printed page do not always match up with what is displayed on-screen. The color generated on the printed page is dependent on the color system used and the particular printer model; not by the colors shown on the monitor. Printer manufacturers have put lots of money into the research of accurate monitor/printer color-matching.

If you go into the tools and/or configuration of the printer on your system, chances are they included a color matching utility, which takes you through several steps, and asks you to compare printouts and make adjustments.  I typically run through this once - when I install the printer.  After that, leave it alone, unless you see a mismatch between monitor and printer occurring. 

Halftones

The simplest type of color printer is a binary device in which the cyan, magenta, yellow and black dots are either 'on' (printed) or 'off' (not printed), with no intermediate levels possible. If ink (or toner) dots can be mixed together to make intermediate colors, then a binary CMYK printer can only print eight 'solid' colors (cyan, magenta, yellow, red, green and blue, plus black and white). Clearly this isn't a big enough palette to deliver good color print quality, which is where halftoning comes in.

Halftoning algorithms divide a printer's native dot resolution into a grid of halftone cells and then turn on varying numbers of dots within these cells in order to mimic a variable dot size. By carefully combining cells containing different proportions of CMYK dots, a halftoning printer can 'fool' the human eye into seeing a palette of millions of colors rather than just a few.

Halftone B&W is the method that newspapers often use.  If you look at a B&W picyure on the front page closely, you will see all the tiny dots.

Paper

Glossy Photo Paper   vs   Standard Paper
(the standard paper absorbs the ink and it spreads)

Most of the current generation of inkjet printers require high-quality coated or glossy paper for the production of photo-realistic output, and this can be very expensive. One of the ultimate aims of inkjet printer manufacturers is to make color printing media-independent, and the attainment of this goal is generally measured by the output quality achieved on plain copier paper. This has vastly improved over the past few years, but coated or glossy paper is still needed to achieve full-color photographic quality. 

Keep in mind that some printers have trouble with glossy paper.  They can have problems separating the sheets through the feed mechanism.  In addition, the ink will often smear if touched.

Thick stock is perfect for cards and/or brochures.  Be careful though, if the stock is too thick it will result in a paper jam.  Fortunately, thick stock paper jams are easy to clear.

Printer Cables - the "Gotcha"

No one has ever underrstood it, and no one ever will.  PRINTERS DO NOT COME WITH A CABLE !!!  It is a fact of life, and I cannot tell you how many of my customers in the past have bought a printer, excitedly brought it home, unboxed it, and then realized there is no cable.  It's that 14 dollars of greed that all printer manufacturers have carried over from generation-to-generation. 

Simplex and Duplex Printing

 

The wizard says - you undoubtedly have a simplex (one-sided) printer.  They do make duplex printers (prints on both sides) but they are very expensive.  For any document of 40 pages or more (one that you need to refer to a lot), it is best to take the time to print it out in duplex mode, by setting the properties in your application to print Odd Pages, then flip the stack over and feed it in again and print the even pages.  This saves trees, but more importantly, it gives you a document that you can get the staples through.  The best way to staple a document that you will refer to a lot, is to place 3 to 5 staples along the left side - then it opens like a book.  If you have a printer that cannot make it through 20 pages without pulling doubles (like mine), then you need to hold the paper as you print the back side, making sure to release only one sheet at a time.  Otherwise once a double is pulled through, the remainder of the stack will be off by one page.

 

 

Spooling

All computers use a small software routine called a print spooler, which basically places print jobs into a queue.  The queue is stored on the hard drive or memory, and it allows you to go and do other things on the PC.  For example, you may have a 20-page document in Microsoft Word that you send to the printer.  Right away you will see a small box appear and the pages quickly counting from 1 to 20 - this finishes within 10 seconds or so, even though the first page has just started to print.  At that point point, the job is "spooled" and you can go surf the web, play a game, or even close Microsoft Word if you like.  The print job is now being handled by the spooler, and no more interaction with the application that initialized the print job is required.  You can also start several print jobs, and they merely stack up in the queue, and print out one job at a time.

 

Print Buffer

Although print jobs are spooled in memory or the hard drive of the computer  .  .  .  the printer itself has it's own memory, called a "buffer".  Many areas of your PC contains buffers, so remember that whenever you hear the term, "buffer", it is referring to a small area of memory.  The printer buffer is RAM (Random Access Memory) just like your PC RAM.  This allows faster printing, by allowing the pages to be first loaded into the printer memory, and then printed.  Without a buffer, the printer would have to be fed a character, print it, then accept another character, print it, and so on.  You can also see this problem on a smaller scale when you send a large, high-resolution image to a printer  .  .  .  it will load up the buffer, print for a while, and complete maybe a fourth of the image until the buffer is empty, then stop as it's buffer  loads up again, and continue.

Some printers can fill the buffer up on-the-fly as they are printing, and therefore even a small buffer will be able to print out large jobs with no apparent hiccups.  But most do not have this feature.

 

Canceling a Print Job

The print spooler is transparent to you.  You usually don't view it, and have no interaction with it.  If you iwsh to view the spooler, you can open it, going to Control Panel and double-clicking on the Printers icon.  There you will see a list of print jobs that are queued for printing.  You can also right-click on a print job, and select cancel from the drop-down menu.   

Unfortunately, most of the time you will only be printing one job, and it is difficult to cancel the current print job.  The reason for this, is that the printer buffer is large enough to load the entire job - and the cancel operation simply causes the PC to stop sending data.  The printer may have 20 pages loaded into it's buffer and continue on it's merry way.  Some printers and the drivers that come with them allow the PC to send a Stop-Print command to the printer, in which case it will finish printing the current page, but flush the rest of the pages out of it's memory.

 

Paper Jams

All printers have paper jams - which is any time the paper becomes stuck somewhere in the printer.  Most are very simple to take care of, and the paper can be pulled out with ease.  However, occasionally, a sever jam will occur, where the paper is either very hard to get to, or is very tightly jammed.  Be very careful in these cases - the paper can become hopelessly jammed !!  Take extreme care when the paper jams up under the rollers inside.  If  you are too forceful, it is very easy to rip out the paper, leaving small bits that you cannot extricate - and in that case the printer will need to go in for servicing.  Or . . . if you are mechanically inclined, you can completely disassemble the printer.

 

Doubles

It is a miracle that printers are able to take one sheet at a time - simply a miracle.  Image how hard it is, even for u, to take just one sheet from the top of a squared-up stack of paper.  You may very well have to live with a certain amount of doubles (or even triples) being fed through the printer.  They do no damage, and you actually lose none of your print job if the double feeds through cleanly.

However, there is a trick I learned from my younger years when I worked at a print shop.  The trick is to get some air between all the sheets, just prior to placing a stack into the feed bin.  The technique is described as follows.  Use this at home and in the office - in fact never place any paper in any printer of Fax machine without doing this first :

1)  Grasp the stack along both sides, holding it in portrait orientation (11" tall, 8.5" wide)

2)  bend the stack to create a "U" shape - keep grasp slightly loose so pages stay snugly

3) tighten your grip, and unbend the stack - do not let the sides slip, as you are trying to place air between the pages during this step

4) relax your grip to let the air out, and tap them a couple of times on the table to square them up

 

Backup Ink or Toner Cartridges

So, so, so important !!!  If you do not keep at least one on hand, you will, by Murphy's Law, run out of ink exactly at the time when you have an excruciatingly important project due ! !

What about Those Little Hypodermic Needle Ink Refill Things ??

No, no, no  .  .  .  the ink is poor quality, and even if it is fine, once the cartridge has been expended - it simply does not distribute ink well any more.  The heads seem to have a limited life.  In addition, the cartridges are sealed, and once you drill a hole in to the side, the ink is exposed to the air.  I really do not know the exact reason why these do not work well, but I know of several people that have purchased them, and all have ended up throwing them out.

OK, What about Recycled Ink Cartridges

Generally, these are fine, and they are less expensive, of course.  Usually you have to order them through the mail.

Redistributing Toner

I think everyone knows this tip - but here goes anyway.  For your B&W laser printer, when you notice the printouts starting to fade - typically the toner has become low in specific areas of the cartridge.  This will be especially true if you notice a light stripe running down the sheets.  Remove the toner cartridge, and tip it at a 45 degree angle, back and forth 10 to 20 times.  In addition, go ahead and shake the cartridge vigorously.  You will probably get another 100 pages or more before the printouts begin to fade again.

Thick Stock - Shiny Stock

You actually can get stunning printouts with the expensive, thick, shiny stock paper.  However, be aware that ink does not dry well on shiny paper, so definitely do not touch it for at least 8 hours.  Also, some printers do not work well with the shiny paper.  Typically a B&W laser does better than a color ink-jet.

If you have problems but still want some excellent paper, there are a number of great looking semi-gloss sheets, and for birthday cards, you can get the semi-gloss card-like stock that has a pre-indented fold in the middle.

Labels

Labels print just fine - just make sure to save the file you created for the labels!  The method is to buy Avery labels, and then go to their website and download the template file that corresponds to that type of label.  They all have a number on the box, and you just go Here and download the Word template.

T-Shirt Iron-Ons

I have not tried these, but it seems they would work just fine.  I would guess you should let the ink dry for quite a while before handling them.