Updated: April 28,2016.

image E Ink’s low contrast—between the text and  background on the screen—annoys many an e-book-lover. I’m one of them. My wife has an even worse problem with the low contrast and refuses to mess with E Ink gizmos. And here E Ink is supposed to be nicer for human eyes than LCDs are.

But what if you could use boldface to thicken the characters and increase the perceived contrast? A quick, easy tweak in Calibre e-book management program will work with many e-book files—not all, alas. What’s more, I’m not sure about this for the Kindle even if the tip is still worth trying on it. Also, you can’t use the bolding trick with DRMed e-books. But considering the number of public domain classics and other nonDRMed books online, give it a shot—your success rate may actually be high. The tweak takes just two minutes if Calibre is on your desktop machine. Here’s what you do:

1. Install the free Calibre software (Web site here, download links here) if you aren’t using it already. Here is help for novices in understanding Calibre. One of Calibre’s developers, John Schember, has written a very useful guide for TeleRead community members, titled The ABCs of format conversion. It’s old but the basics still apply.

2. Click on the Preferences at the top of your screen toward the right. You’ll see gears.

3. Under the Conversion category, you’ll see Common Options. Click on that.

4. Click on Styling.

4. Then within the box labeled Extra CSS, insert the following code: body { font-weight: bold }

5. Click OK.

With many e-book files and maybe even most, your books will be all-bolded when you convert. You can even “convert” within the same format—ePub to ePub. Mercy toward your eyes!

Of course, the real solution to the contrast problem would be for device-makers to use the Embolden command—turn everything into boldface—that the Cybook Gen3 uses. Improved E Ink tech should also help. The contrast of the newer displays is better than it used to be. It just isn’t good enough yet for Carly and me.

Thanks: To Kovid Goyal, Calibre’s brilliant and ever-diligent developer. I tried the bold command but didn’t see results, until I went on to other files after he said that bolding wouldn’t work with all. Now how about some feedback? How does the trick work for you?

Image credit: CC-licensed eye image from Orangeacid.

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  1. hi,
    This worked on a PDF ebook(lucifer’s lodge by william.h.kennedy)i bought from the lulu e-store.

    I used the calibre tool/hack to convert from PDF to E-PUB.

    The font em-boldening does work but the font size wasn’t the same..it was larger than normal and the formatting was different.

  2. This way works OK, but misses all the emphatic bolded text of the original texts. A much more elegant and almost of equal ease of implementing is the use of custom fonts. For example in the Sony series, all you need to do is drop some fonts in the data folder of your reader and then use the font-face html in the css area of Calibre. To get very easy step by step instructions, just see here.

    • Sadly, that’s no longer an option for Kindle. It *used* to be that easy but Amazon took that ability away in later firmware updates. You can do that in Calibre on a per book basis but that increases file sizes, considerably.

    • Or (c) a device NOT manufactured by Amazon. Kobo, for instance, does a much better job than Amazon in providing differing font weights and various 3rd parties — like KoReader on Kobo — enhance it even further.

      For some reason, Bezos has chosen to impose *his* typography preferences on all users; the Amazon message being “you’ll read the damned book like we say, and you’ll like it”.

      The funny-looking bald dude apparently has control issues.

  3. So this explains the scourge of bolded text I’ve had to put up when downloading ebooks. My Kindle3’s contrast ratio is pretty high and doesn’t need this “hack”. I also can’t stand to read bold body text – it’s like someone’s shouting at me nonstop.

    At least I now know how to use Extra CSS to remove the bolded text in Calibre without having to keep searching for a copy with normal text.

    • For editable formats (epub & azw3), you can also go into Calibre’s edit program and delete the hard-wired formatting. This comes in handy for (presumably do-it-yourself Indie) authors who’ve screwed the pooch on their formatting; inserting styles which can’t be overriden like fonts, indents, justification, etc.

      At times, you’ll also see ebooks with huge file sizes. Some are legitimately inflated because of (necessary) images but, often this inflation is due to idiotic graphics announcing chapter headings AND included fonts. Calibre’s editor allows you to delete all that crap and reduce the size dramatically.