Kobo type and choices for readability

[EldRick]

I'm a hawk about typography and readability, so I returned my first Kobo Touch within hours of receiving it - the two fonts offered did not meet my needs, and were nearly unreadable when set to suit my reading.

However, after seeing the huge advance Kobo made with the 1.9.5 software update, I ordered another one, and received it yesterday.

After updating it and loading a few books onto it, I spend most of the rest of the day playing with type, to see what I could do to meet my needs. Here's where I'm looking for, and where I'm at with it.

I am a speed-reader. I was once been tested reading newspaper material at 3000 wpm, with excellent comprehension. I've also developed Postscript fonts and scalable logos for both low-res displays and high-res printers, and have taught classes on the topic. I state this simply to point out that I know a bit about type. I'm also on my third e-reader. I have a K3, a Nook STR, and now a Kobo Touch, so I can easily make comparisons between these three current products.

The major typographic issue in all of these products is the low-resolution of the e-ink screen - roughly the same as a 1984-vintage dot-matrix printer - ~170dpi. This means that a 12-point character is only 28 pixels tall, and a dozen or so dots wide, which cannot support complex typography or display shaded fonts with any visual accuracy at all. For example, a stroke in any character on a Kobo screen is going have a range of 1- to 4-pixels in width, not the 50 or so that would be available for printing on any inexpensive ink-jet or laser printer.

To support my reading habit (average 2-3 novels/week), I use specific settings to make the type suitable for fast reading. When I started looking for typefaces for the Kobo, these are the criteria I used:

This image shows the terminology, and is a perfect example of a typeface that will work badly at 8- to 10-point on a KT screen, for all the reasons below.


- Serif fonts only, San-serif type is rarely used in publishing, because it is not as readable - the serifs contribute a lot to your ability to distinguish between similar characters.

- The serifs cannot be elegant, tapered, pointy, or depend on smooth fillets into the character body. A low-res display cannot display curved, narrow, or tapered serifs, as there are not enough pixels, and rendering commonly errs on serifs for this reason.

- Must be readable at 9- or 10- point size. My eyes are good (with contact lenses), and I want as many lines on a screen as possible, to minimize page-turns.

- Medium stroke width. A one- or two-pixel stroke nearly disappears on the KT screen. For a perfect example, look at the page numbers at the bottom of any screen of a book - that's single-pixel stroke width = impossible to read. To stand out on the screen, the strokes need to be in the 3-4 pixel-width range. While I have no trouble reading small type, the combination of old eyes, contact lenses, and reading glasses reduces visual contrast, so I want a slightly-bolded font.

- Consistent and constant stroke width. Variable stroke width, as in the example, appears blotchy if you don't have enough dots, and this also tends to create dropouts, where there are visible "gaps" in the characters where the width drops to a single pixel. Classical fonts were designed to look great on paper by shading to emphasize letterform shapes, and display poorly at low resolution.

- Rounded characters, with "fat" ovals. A low-res screen cannot show fine gradations in shape, so a rounded body shape displays much better than a condensed font, and oblong shapes turn into flat-sided ovals.

- Tall X-height. The body of lower-case letters should be 65-75% of the cap height for low-res display. This simply makes the characters more easily distinguishable, and speeds recognition. The example is maybe 55% X-height.

- Moderate descender and ascender height vs.cap height. Too-tall characters reduce to permissible line spacing.

So I started by selecting a few typefaces from those supplied with my Mac and with MS-Office on the Mac, but discovered that the selection of TTF and OTF fonts was pretty limited. I could convert from other formats into OTF, but that's more work than I'm willing to invest at the moment.

I wound up going to Google, for the web page fonts they offer, which were specifically designed for low-res display.

So (finally) here's what serif fonts are in use on my KT at the moment:

- First, kudos to the Kobo team for the new-with-1.9.5 Rockwell font. It meets all of my criteria, is quite readable at 8- to 10-point sizes, and is very comfortable for extensive reading. If I could pick only one serif font for the KT, it would be Rockwell. It's not pretty, but is very functional.

- I added Minion Pro from my Mac. It's not ideal, as it is a bit light in smaller sizes, but nice for 11- or 12-point reading.

- From Google (http://www.google.com/webfonts/) I loaded Arvo, Crimson Text, Kameron, and Kreon. I keep switching, but i'm currently using Arvo, as a slightly less-dense and less-dark choice than Rockwell.

- Kobos Amasis, Delima, and Georgia do not work well at smaller sizes. I find them unsuitable for my purposes.

- Text ghosting remains a significant issue on the KT, but at least 1.9.5 delivered a workaround for the problem.

So that's that - if anyone else has similar needs and finds typefaces that work well at small sizes on the Kobo, chip in.

[PeterT]

WOW... Excellent information here. I learnt a lot. Now if ONLY my birthday was sooner so the wife would get me my KT

I look forward to experimenting myself.

[jackastor]

not worth the comment

[TedJ]

Thank you for that, EldRick. I look forward to trying out some of your suggestions when my KT finally arrives. Agree with you 100% on the use of serif fonts only... sans serif fonts should be reserved for titles and block headings.

EldRick, what a great post! When my KT arrives (it's been a month since I ordered... well, I live in Europe) I have to try a lot of fonts Typography is really interesting (and important) I think, and I enjoy a nice, good font.

Oh well, I read the news of the new "Google Reader" today... it's an iRiver Story HD coupled with some Google ebook access. This got me researching.... oh the humanity display! It's 6 inch too, but at 1024x768 pixels. That's 64% more pixels than the KT's 800x600 I regret having ordered the KT, a bit at least

Have a look at the screen pictures:

http://www.techbrief.co.in/06/28/a-s...iver-story-hd/

The screen is manufactured by LG. I don't like all the buttons. I think this is a bit more resolution than a 1984-vintage dot-matrix printer

EDIT:
I don't want to hijack EldRicks thread, so I'm adding this information here:

- Display is manufactured by LG
- uses the same Freescale i.MX508 processor architecture as the Kobo Touch

Originally Posted by Benjamin Buford

EldRick, what a great post! When my KT arrives (it's been a month since I ordered... well, I live in Europe) I have to try a lot of fonts Typography is really interesing I think, and I enjoy a nice, good font.

Oh well, I read the news of the new "Google Reader" today... it's an iRiver Story HD coupled with some Google ebook access. This got me researching.... oh the humanity display! It's 6 inch too, but at 1024x768 pixels. That's 64% more pixels than the KT's 800x600 I regret having ordered the KT, a bit at least

Have a look at the screen pictures:

http://www.techbrief.co.in/06/28/a-s...iver-story-hd/

The screen is manufactured by LG. I don't like all the buttons. I think this is a bit more resolution than a 1984-vintage dot-matrix printer

That review didn't really give much information, and nearly no specs. I would like to know more about the screen.

Can't try it out yet, but Droid Serif looks like it could look great on an eink screen! I'm not a great fan of Rockwell/Arvo, looks so "blocky"

As far as serif versus sans serif, that is obviously a user preference. However, as screens become more paperlike in the ability to display clean, crisp text, the more likely that serif fonts will work. A lot of scholarly studies were conducted in past years and decades to explore why people chose serif or sans serif. The studies showed that for printed material, which generally had fairly clean and crisp text, most people chose serif. But for computer monitors people generally chose sans serif.

The major factor was that monitors in that time rarely had more that 96 dots per inch resolution, often as low as 72 dpi for Macs, and the pitch (amount of space between dots) was fairly large. It was very noticeable pitch as you could easily discern a bunch of dots surrounded by black (or dark) space. it gave a blurry rendering of text which meant that all the little serif bits merely confused the eyes and caused eyestrain.

As viewing monitors and screens have improved, so has the usefulness of serif on them. I still had trouble with serif fonts on pre-Pearl eInk screens and most LCD screens. But Pearl eInk is crisp enough that I can read thicker serif fonts for extended periods on same. I still have trouble with serif on PC monitors and on my iPad (133 dpi low resolution) screen, but my iPod touch 4G with its 325 dpi Retina display makes almost any font readable for long periods.

EDIT: BTW, the difference between pre-Pearl and Pearl eInk screens has nothing to do with resolution as far as I can tell. The 6" screens were both 600 x 800 pixels. The difference is that pre-Pearl screens seemed to render text somewhere in between a light-gray and medium-gray, whereas Pearl screens seem to render text somewhere in between a dark-gray and black. I'm sure there are other improvements as well, but the darker text greatly enhanced the readability.

[EldRick]

viewing monitors and screens have improved, so has the usefulness of serif on them. I still had trouble with serif fonts on pre-Pearl eInk screens and most LCD screens. But Pearl eInk is crisp enough that I can read thicker serif fonts for extended periods on same.

Totally agree with the whole post.

[tomsem]

What's the range of text sizes (in points) on with the current firmware (1.9.5)? How does this compare with Nook Touch and Kindle?

Originally Posted by tomsem

What's the range of text sizes (in points) on with the current firmware (1.9.5)? How does this compare with Nook Touch and Kindle?

I've got no clue as to point size, but a kePub has about 24 font sizes available. I got a bit distracted counting them, so hence "about".

Here are three photos showing Lexia DaMa (a sideloaded) font at the following sizes:

• Size 1, smallest
• Size 7, my preference
• Size 24, largest

As you can probably see the line spacing was set for my preference with size 7 of this font. At size 1, if I could read that small of text, I would most likely use a smaller line spacing to compensate for the tiny font size.
...

[EldRick]

One comparison between the NT/K3 and the KT, is that that both the K3 and NT have a large gap in sizes - I find that you usually have a choice on them of just a little too small, or way too large - they seem to jump from roughly 10-pt to maybe 16-pt, with no sizes in between.

The KT, by contrast, has much finer granularity in sizes.

[Atilla]

In order to access italic and bold fonts when they are called for in a book, do we have to copy all versions of the said font in our fonts folder?

If we only copy the regular font, will KT make them bold or italic when such is asked in the book format?

[Joe563]

Originally Posted by Atilla

In order to access italic and bold fonts when they are called for in a book, do we have to copy all versions of the said font in our fonts folder?

If we only copy the regular font, will KT make them bold or italic when such is asked in the book format?

For best results, for each typeface, you should copy the regular, bold, italic and bold italic fonts. If you only copy the regular font, the reader does attempt to manipulate the font to show italic and bold but it does not look as good as the true italic or bold font.