by Chris Woodford. Last updated: May 13, 2019.
Back in the 19th century English author, Martin Tupper wrote: "A good book is the best of friends, the same today and for ever."
It's true: books are friendly, familiar, and loveable and that
probably explains why it's taking us so long to get used to
the idea of portable electronic books. But with the arrival of a new
generation of electronic book readers, such as the Sony Reader,
and Amazon Kindle, the days of the printed word just might be numbered.
Let's take a closer look at electronic books (ebooks) and find out how
Photo: Above: Amazon Kindle Paperwhite electronic book reader. Below: The Kindle's now obsolete rival, the Sony Reader PRS-350, was considerably smaller and designed to carry around in your pocket. Both are smaller than the first generation of Kindles, because their touch-sensitive screens do away with the need for a separate keyboard.
Two in one: books... and the information they contain
Think of a book and you think of a single object, but the books we
read are actually two things in one: there's the information (the words
and pictures and their meaning) and there's the physical object (the
paper, cardboard, and ink) that contains them. Sometimes the physical
part of a book is as important as the information it carries: it's
really true that we judge books by their covers—at least when we're
standing in shops deciding which ones to buy—and that's why publishers
devote so much attention to making their books look attractive. But, a
lot of the time, the information is much more important to us and we
don't really care how it's delivered. That's why many of us now turn to
the Web when we want to find things
out instead of visiting the local library.
In short, we've learned to split off the information we need from
the way it's delivered. Ebooks take this idea a step further. When we
talk about an ebook, we really mean a digital version of a printed
text that we can read on a handheld electronic device like a miniature
laptop computer— two quite
separate things, once again.
How do you store a book in electronic form?
An ebook is really just a computer file full of words (and
sometimes images). In theory, you could make an ebook just by typing
information into a word processor. The file you save has all the
elements of an electronic book: you can read the information on a
computer, search it for keywords, or share it easily with someone else.
The first attempt to create a worldwide library of ebooks was called
and it's still running today. Long before the World Wide Web came
along, a bunch of dedicated Gutenberg volunteers took printed books and
scanned or typed them into their computers to make electronic files
they could share. For legal reasons, these books were (and still are) mostly classic
old volumes that had fallen out of copyright. The electronic versions
of these printed books are very basic, text-only computer files stored
in a format called ASCII (American Standard Code for
Information Interchange)—a way of representing letters, numbers, and
symbols with the numbers 0-255 that virtually every computer can
Photo: The Amazon Kindle Paperwhite electronic book reader (left) alongside the rival Sony eReader (right). This Kindle has a fairly unobtrusive set of LED lights built around the screen to make reading easier in the dim evening light. Although it's hard to see in this photo, the Paperwhite does have a much whiter screen than the Sony. Even so, I find the text much sharper on the Sony. It's also worth pointing out that I've owned two of these Sonys and the screen on one was noticeably better than the other. In other words, the quality of ebook screens definitely does vary.
The problem with ASCII is that the text contains very little
formatting information: you can't distinguish headings from text,
there's only one basic font, and there's no bold or italics. That's why
people developed much more sophisticated electronic files like PDF
(Portable Document Format). The basic idea of PDF was to store an
almost exact replica of a printed document in an electronic file that
people could easily read on screens or print out, if they preferred.
The HTML files people use to create web pages are another kind
of electronic information. Every HTML page on a website is a bit like a
separate page in a book, but the links on web pages mean you can easily
hop around until you find exactly the information you want. The links
on websites give you powerfully interconnected information that is
often much quicker to use than a library of printed books.
The greatest strength of ASCII, PDF, and HTML files (you can read
them on any computer) is also their greatest weakness: who wants to sit
staring at a computer screen, reading thousands of words? Most screens
are much less sharp than the type in a printed book and it quickly
tires your eyes reading in this way. Even if you can store lots of
books on your computer, you can't really take it to bed with you or
read it on the beach or in the bath-tub! Now, there's nothing to stop
you downloading simple text files onto something like an iPod or a
cellphone and reading them, very slowly and painfully, from the small
LCD display—but it's not most people's idea of
curling up with a good book. What we really need is something with the
power of a computer, the portability of a cellphone,
and the friendliness and readability of a printed book. And that's
exactly where electronic book readers come in.
How do you read an electronic book file?
An electronic book reader is a small, portable computer designed for
reading books stored in a digital format such as ASCII, PDF, HTML, RTF, or
another similar format. (Currently the two most popular ebook formats are
EPUB, a worldwide, open standard that evolved from an earlier standard called OEB (Open ebook) and widely used by Sony Readers and most other ebook readers, and AZW, a
proprietary format developed by Amazon and currently readable only
on its Kindle reader. There are a few other formats including MOBI and LRF,
but you don't hear about them so much.) However you go about it, books take up very little space when you store
them in electronic format: you could easily fit 10,000 electronic
copies of the Bible onto a single DVD. Most ebook readers can store hundreds
or even thousands of titles at a time and most now have Wi-Fi Internet
connections so you can download more books whenever you wish.
Photo: You can read electronic books right now, even if you don't have a handheld ebook reader. There's free electronic book software available for all the popular operating systems. You can also download versions of the Amazon Kindle that work on a PC, Mac, iPod/iPad, iPhone, or Android smartphone. Here's the Caliber electronic book reader running on a normal computer screen, showing the first page of F.Scott Fitzgerald's The Beautiful and Damned.
The most important part of an ebook reader is the screen. The first
ebooks used small versions of LCD laptop screens which have a
resolution (sharpness) of about 35 pixels per cm (90 pixels per inch).
You could easily see the dots making up the letters and it was quite
tiring to read for more than a few minutes at a time. The latest
ebooks use an entirely different technology called electronic ink. Instead of
using LCD displays, they show words and letters using tiny, black and
white plastic granules that move about inside microscopic, spherical
capsules under precise electronic control. Displays like this have
about twice the resolution of ordinary computer screens, are clearly
visible in sunlight, and use much less power. In fact, they're almost
as sharp and easy to read as printed paper. We'll see how
these screens work in a moment.
The lack of books in electronic format was one of the things that
used to put people off using ebook readers—and that's what made Amazon.com's
Kindle reader such an instant success. Amazon already worked
with virtually all the world's publishers as a bookseller, so it was
able to make huge numbers of titles available for Kindle in electronic
format—over 88,000 books were available on the launch date.
Today, most books are available in ebook format as well as print,
and many old, long-out-of-print titles have also been resurrected in
How does E Ink® work?
Photo: Computer screens as we knew them in the late 1970s and early 1980s. At that time, the best screens could display no more than about 64,000 pixels and often just uppercase text or very crude "pixelated" (square block) graphics. Computer games like Space Invaders, shown here, were very primitive—but still highly addictive!
Since electronic ink has been crucial to the success of ebooks, let's
now take a detailed look at how it works.
You're probably reading these words in the same way that I am—by staring at
a flat, LCD computer screen. For people over the age of about 35, who
grew up with computers that used blocky green and black screens with
just 40 characters across and 25 down, modern screens are wonderful
and amazing. But they still have their drawbacks. Look closely, and
you can see jagged edges to the letters. Try to read an LCD screen in
direct sunlight and (unless the screen has a very bright backlight), you'll really
struggle. But the worse thing is that LCD screens lack the
lightness, portability, and sheer user-friendliness of ink-printed paper:
you can happily read a book for hours, but try the same trick with a
computer screen and your eyes will quickly tire.
Photo: LCD versus E Ink®: The E Ink display on a Sony Reader (bottom) is much sharper and easier to read than a typical LCD screen (top). Magnifying by about 8–10 times and zooming in on a single word, you can see why. The E Ink display makes sharper letters with a uniformly white background. The LCD display blurs its letters with anti-aliasing to make them less jagged, though that makes them harder to read close up. The red, blue, and green colored pixels used to make up the LCD's "white" background are also much more noticeable. Unlike the E Ink display, an
LCD does not use a true white background: it relies on your eye and brain to fuse colored pixels instead. The resolution of E Ink is also far greater: typical LCD displays use around 90 pixels per inch, whereas E Ink displays use at least twice as many pixels.
Back in the early 1970s, the Xerox Corporation that had pioneered
photocopiers a decade earlier became concerned about the threat that
computers might pose to its core ink-and-paper business: if everyone
started using computers, and offices became paperless, what would
happen to a company so utterly dependent on paper technology? It was
for that reason that Xerox pumped huge amounts of money into PARC™,
(Palto Alto Research Center), the now-legendary campus where modern,
user-friendly personal computing was pioneered. Among the many innovations
developed there were personal computers that used a
graphical user interface
(the "desktop" screen featuring icons, later copied by the Apple Macintosh® and Microsoft Windows®),
laser printers... and electronic paper, which was invented
by PARC researcher Nick Sheridon.
The basic idea of electronic ink and paper was (and remains) very simple: to produce an electronic display
with all the control and convenience of a computer screen but the
readability, portability, and user-friendliness of paper.
How does electronic ink and paper work?
Most electronic ink and paper screens use a technology called
electrophoresis, which sounds complex but simply means using
electricity to move tiny particles (in this case ink) through a fluid
(in this case a liquid or gel). Other uses of electrophoresis
include DNA testing, where electricity is used to separate the parts
of a DNA sample by making them move across a gel, which enables them
to be compared with other samples and identified.
In one of the best-known electronic ink products, called E Ink® and used
in ebooks such as the Amazon Kindle, there are millions of microcapsules,
roughly the same diameter as a human hair, each of
which is the equivalent of a single pixel (one of the tiny squares or
rectangles from which the picture on a computer or TV screen is built
up). Each capsule is filled with a clear fluid and contains two kinds
of tiny ink granules: white ones (which are positively charged) and black
ones (which are negatively charged). The capsules are suspended
between electrodes switched on and off by an electronic circuit, and each one
can be controlled individually. By changing the electric field
between the electrodes, it's possible to make the white or black
granules move to the top of a capsule (the part closest to the
reader's eye) so it appears like a white or black pixel. By controlling
large numbers of pixels in this way, it's possible to display text or
Animation: Electronic ink works through electrophoresis. Each pixel (microcapsule) in the display (the gray circle) contains black (negatively charged) and white (positively charged) ink granules. When a positive field (shown in blue) is applied to the top electrode, the black capsules migrate to the top, making the pixel look black when seen from above; switching the field over makes the granules change position so the pixel appears white.
Advantages and disadvantages of electronic ink
If you've tried reading an electronic book, you'll know that electronic ink
and paper is much easier to read from for long periods than an LCD
computer screen. Since the microcapsules stay in position
indefinitely, with little or no electric current, electronic ink
displays have extremely low power consumption. A typical ebook reader
with an E Ink display can be used for something like 2–4 weeks of
average everyday reading on a single charge—which is much less
power than a laptop, tablet, or smartphone. Low power consumption means
low energy use and that translates into an
environmental benefit; in
other words, electronic ink and paper is environmentally friendly.
What about the energy needed to manufacture your reader in the first place?
According to British environmental auditor Nicola Terry,
who's done the math, you've only to read 20–70 ebooks to offset that energy; the Cleantech group has estimated
that a Kindle makes savings in carbon emissions after just one year's use.
That sounds great, but do bear in mind that emissions from reading and producing books
are a trivial part of most people's total emissions (the majority of which
stem from transport, consumed goods, home heating, and so on).
The disadvantages are less obvious until you start using electronic ink
in earnest. First, although the displays work excellently in bright
indoor light and daylight, including direct sunlight, they have no
light of their own (unlike LCD displays, which have backlights shining through
them from back to front so you can see them). That makes them hard to use in poor indoor light,
especially in the evenings, which is why many early ebook readers were sold
with clumsy addon lamps. Fortunately, firms like Amazon now offer readers
with built-in lights (like the Kindle Paperwhite in our top photo), so the
problem of straining over ebooks in the dark has now largely disappeared.
Photo: Night and day, are you the one? Here I've propped a Sony Reader against the screen of a conventional laptop and photographed it in different light conditions. Left: In bright light or daytime outdoors, electronic ink displays are much easier to read than backlit LCD displays, which become virtually invisible. Right: In dark indoor light in the evenings, things are reversed: LCDs are much easier to read and electronic ink displays are a struggle to decipher unless you sit in strong light (or use a clip-on light attachment).
Electronic ink also takes much
longer to build up the image of a page than an LCD screen, which means
it's unsuitable for everyday computer displays using any kind of
moving image (and completely unsuitable for fast-moving images such
as computer games and videos). Sometimes parts of a previous page
linger on as "ghosts" until you've turned another page or
two. You've probably noticed that, when you "turn the page"
of an electronic book, the entire screen momentarily flashes black
before the new page is displayed? That's a rather clumsy compromise
to prevent ghosts, in which the screen tries to erase the previous
page before displaying a new one (a bit like
Another major disadvantage is that most electronic ink displays are currently
black and white. Crude color displays do exist (E Ink has produced one called Triton since 2010, in
which a layer of red, green, and blue color filters is mounted over
the usual black-and-white microcapsules) and better ones are in development, but they're much more expensive than their black-and-white electronic paper (or LCD equivalents) and only display
a relatively small number of colors (Triton can manage 4000, compared to about 17 million on a decent
LCD). In time, we're bound to have color electronic books and magazines, but don't hold your breath. Amazon's Jeff Bezos, speaking in mid-2009, said that a color Kindle ebook
reader was "multiple years" away: "I've seen the color displays in the laboratory and I can assure you they're not ready for prime time." That was why, when Amazon first shipped its color Kindle Fire™ product in September 2011, it had an LCD display. In May 2016, E Ink announced a color replacement for Triton called Advanced Color ePaper (ACeP), but it's still some way from making it into Kindles and other ebook readers.
Which electronic book reader should I buy?
Kindle, Sony Reader, Nook, Elonex—which one should you buy? The decision is a little easier than it used to be now Sony has (regrettably) stopped making ebook readers, though I'd still recommend looking out for cheap secondhand Sonys on auction sites. (My first Sony Reader cost a little under US$200; when I broke it, five years later, I picked up a mint-condition replacement on eBay for about US$25!)
They're all broadly similar: they're all light, portable, and handheld and they all have large internal
flash memories that hold hundreds or thousands of books.
Some have touchscreens; others (like the older and cheaper Kindles) have miniature
keyboards. Some have wireless connections for downloading more books; others (such as the Sony Readers) have to be connected to a computer with a USB cable. If you connect with USB, running an ebook reader is rather like running an iPod or MP3 player: typically you maintain a library on your PC with a piece of software similar to iTunes, to which you add and remove books and other documents. When you plug in your reader, it "syncs" (synchronizes) its internal
memory with the library on your PC, adding any new books and deleting any unwanted ones. If you have a wireless reader, you maintain your library on the reader itself or in the cloud (stored on a remote computer somewhere and accessed online), adding and removing books directly. So... wireless or cable?
It's not a big issue, I don't think, though elderly people who have little experience of using a computer may find buying books easier
with something like a wireless Kindle with its built-in, easy-to-use bookstore).
Photo: Horses for courses: Portable versions of the Sony Reader have a much smaller page size than a typical hardbook book. That's great if you want to carry your reader in your jacket pocket or your handbag so you can read while you're travelling. It's much less attractive if you do most of your reading at home: the smaller the screen, the more often you'll need to turn the pages. This is one example of why it pays to think about how you're going to use an ebook reader before you buy it.
Displays and batteries
The best and most expensive readers use extremely high-resolution E Ink screens that work better in daylight than at night
(you'll need good indoor lighting or a clip-on light if you're planning to do most of your e-reading in the evenings); LCD-screen readers (such as the Elonex) have backlit screens that favor indoor use and (like computer screens) can be tricky to read in bright sunlight. Amazon's current state-of-the-art reader, the Kindle Paperwhite, has discreet little LED lights built around the edge of the screen that make a noticeable difference when you're reading indoors in the dim evening light.
E Ink apparently uses energy only when you turn the pages, so the Sony Reader can happily survive for about two weeks of very heavy use on a single charge of the batteries, while the Kindle Paperwhite claims up to eight weeks of battery time. That means it's also very environmentally friendly to read books or documents from a handheld ebook reader compared to reading them on a computer screen.
Some ebook readers can cope with ebooks in all kinds of different formats. The Sony Reader, for example, lets you read Microsoft Word and PDF files, as well as standard formats such as EPUB. The PDF viewer is really neat, allowing you to rotate the screen or scroll documents column-by-column for easy reading. The Amazon Kindle doesn't currently support the EPUB format, but it does allow you to view other file formats such as PDF. You can also mail documents to your Kindle, which is something you can't do on a Sony.
Photo: You can use the Sony Reader in "landscape" orientation if you find that easier, though you have to switch it over manually from the keyboard (unlike with a smartphone, the display doesn't rotate itself). Here I'm reading a PDF file of Sustainable Energy—Without the hot air by physicist David MacKay. If environmental issues matter to you, reading documents on an ebook reader like this might appeal, because it uses a fraction as much energy as a laptop. The text is much more legible than it appears in this photograph.
Most books currently produced by publishers are copyrighted, which means you can (and should) expect to pay a fair price if you want to use them.
A decade ago, when I first wrote this article, relatively few publishers had embraced ebooks. Today, most publishers make most new books
available in at least one electronic format, and many sell direct to readers from their own websites, but
they're taking their time making backlist and out-of-print titles available this way.
Generally, it's relatively easy to find new mass-market bestsellers in ebook format but harder to find more specialized books and quality, literary fiction. Public domain classics are the easiest books to find in ebook format, largely thanks to the sterling and visionary work of
(and, more recently, the Open Library, which currently
promises over a million free ebook titles).
If you enjoy reading classic novels, buying an ebook reader is probably a no-brainer; if you're more a fan of
modern literary fiction, you might have a harder time finding what you want in digital form.
Unfortunately, the standard of production for ebooks is noticeably lower and sloppier than it is for
print books: expect to find scanning and formatting errors, missing endnotes, redacted photos (because of copyright issues),
artworks that are blurred or don't display properly, tables that don't fit on the screen, and worse.
It's quite obvious that publishers don't apply the same high editorial and proofreading standards to printed books and ebooks.
Take a moment to send complaints direct to a publisher whenever you find a really sloppy ebook, copy the author in if you can find contact details for them—and be sure to ask for a refund.
If you buy copyright ebooks from either Amazon or another outlet, you'll find they're protected by what's called DRM (digital rights management)—effectively a kind of encryption that prevents people from distributing pirate copies of books illegally. Amazon uses its own DRM system, while Sony (and others) use a system developed by Adobe called Adobe Digital Editions (ADE), which requires you to register
your reader the first time you use it. DRM protection restricts what you can do with books you've bought, but it's not necessarily the drawback it seems. First, it's very much a necessity from a publisher's point of view: it's only because ebook readers like the Kindle have DRM protection built in that publishers are starting to take what they see as a major risk in making their books available in digital formats. Another advantage of DRM is that it allows libraries to lend people ebooks for limited periods of time (using systems like
and cloudLibrary™). I'm delighted to find I can log in to my local library and download, for free, for periods of up to 14 days, a fair selection of a few hundred popular ebooks. Once the borrowing time has expired, the books delete themselves automatically from my reader. Be warned that some libraries allow lending only in EPUB and PDF format, and you might not be able to borrow books on a Kindle.
Who invented electronic books?
- ~3000BCE: Ancient Egyptians make the first paper from the stem of the papyrus plant.
- 105CE: Chinaman Ts'ai Lun develops modern paper from hemp fiber.
- ~1450: German Johannes Gutenberg invents the modern process of printing with movable metal type, which leads to a vast increase in the popularity of books.
- 1945: In a famous article in Atlantic Monthly called As We May Think, US government scientist Vannevar Bush proposes a kind of desk-sized memory store called Memex, which has some of the features later incorporated into electronic books and the World Wide Web (WWW).
- 1968: Computer scientist Alan Kay imagines a portable computerized book, which he nicknames the Dynabook.
- 1971: Michael Hart launches Project Gutenberg at the University of Illinois: an electronic repository for classic, out-of-copyright books.
- 1990: Sony launches its Data Discman, a portable electronic reader costing $550 that stores and reads books from compact discs (CD-ROMs). It is a commercial flop.
- 1990s: Encyclopedia publishers such as Britannica and Dorling Kindersley (DK) experiment with making their books available on interactive CD-ROMs. DK wins many awards for its CD-ROMs, but closes its multimedia business in the late 1990s as competition mounts from the Internet.
- Late 1990s: Several new handheld, electronic book readers are launched, including the SoftBook, RocketBook, and Everybook—but fail to make much impact on the marketplace.
- 2000: Best-selling horror author Stephen King launches a short novel called Riding the Bullet in electronic format and sells over half a million copies.
- 2001: Larry Sanger and Jimmy Wales give the world Wikipedia—an electronic encyclopedia anyone can contribute to.
- 2007: Amazon.com launches its wireless Kindle reader with thousands of electronic books available in electronic format, along with newspapers, RSS feeds, and other forms of "digital content."
- 2010: Amazon Kindle becomes Amazon's number one bestselling product, confirming that electronic books (and readers) really have arrived!
- 2010: E Ink announces Triton, a colored version of its ebook screen technology.
- 2011: Project Gutenberg celebrates 40 years of producing and distributing electronic books.
- 2014: A report by Pricewaterhouse Coopers predicts ebooks will outsell printed books by 2018, but UK bookstore founder Tim Waterstone argues the market will go into decline.
- 2014: Sony stops selling its Readers after growing sales of smartphones and tablets cause a major fall in sales.
- 2015: The Association of American Publishers reports a dramatic reversal of fortune, with a 10 percent fall in sales of ebooks (which still account for only a fifth of the market).
- 2016: E Ink announces Advanced Color ePaper (ACeP), an improved color screen.
- 2018: Walmart announces it will challenge Amazon's dominance of the ebook market in a bold partnership with Japanese firm Rakuten.
Find out more
On this website
- Philip Pullman leads call for UK government action on ebook piracy by Alison Flood, The Guardian, 8 April 2019. Around one in six ebooks are pirated, according to Britain's Society of Authors.
- 'Ebooks are stupid', says head of one of world's biggest publishers by Alison Flood, The Guardian, 20 February 2018. Publishers have failed to exploit the unique properties of digital information, argues the head of Hachette Livre.
- The Plot Twist: E-Book Sales Slip, and Print Is Far From Dead by Alexandra Alter. The New York Times. September 22, 2015. Why has there been a dramatic decline in ebook sales and a resurgence in printed books?
- The Language of E-books by Paul McFedries. IEEE Spectrum, 28 January 2015. A look at the various technical terms used to describe different kinds of ebooks (and related technologies).
- E-books to outsell print by 2018 says new report: BBC News, 4 June 2014. A new market study predicts that the British market for ebooks will reach £1 billion by 2018. Not everyone agrees the ebook revolution will continue, as you can see from another BBC story,
Tim Waterstone 'predicts e-book decline', from 31 March 2014.
- Which is the best format for ebooks? by Jack Schofield, The Guardian, 15 September 2011. Jack explores the differences between EPUB, AZW, MOBI, and a plethora of other ebook file formats that you might find confusing.
- Public libraries open doors for e-books by Mark Say, The Guardian, 14 April 2011. How libraries can lend books in electronic format, thanks to systems such as OverDrive, ebrary, and Public Library Online.
- Why US schools are embracing ebooks and iPads: BBC Click, 27 June 2011. How schools are turning to ebooks, iPads, and cloud computing.
- Is the writing on the wall for paper? by Bill Thompson. A thoughtful technology writer sees different strengths and weaknesses in paper and electronic displays and sees both technologies surviving side-by-side for some time yet.
More about E Ink
- E Ink Corporation: Lots of interesting technical information and background.
- YouTube: E Ink: E Ink's YouTube channel has some great little videos demonstrating black-and-white and color displays.
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E Ink is a registered trademark of E Ink Corporation.
Kindle and Paperwhite are trademarks of Amazon.com, Inc or its associated companies.
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