From the Kindle FAQ at Amazon forums:

Q: I know Kindle allows you to adjust [text] to an extent, but I from the illustrations I can't determine how it would really appear. Any information on this?
A: Kindle offers six different font sizes which correspond approximately to the following Microsoft Word standard font sizes:
1 = 7pt
2 = 9pt
3 = 11 pt
4 = 14 pt
5 = 17 pt
6 = 20 pt

So, if I am making a book from scratch thru Mobi-Creator, the "normal" typestyle in Word is 12 points. If I make the bodycopy of the text 12 points, does that hit at the [ 3 ] size above, leaving 2 smaller choices and 3 larger? (still making books to send to Dad, and just need to know how to predict what he will see).

-bjc

A MOBI e-book is essentially HTML, and in particular it does not typically include explicit font sizes. By default the body of the text will be fully justified and will be in the font size selected in the Kindle menu (so all e-books have the same user-selected font size). I have never used BD, but I assume this is the case here too. So using 12-pt on the DOC file is ok.

Once you have a PRC file from BD, you can use the Windows MobiPocket Reader to see what it will look like on the Kindle. Note that the Kindle only has one font, and it is a Sans Serif font so if you view the document in MobiPocket Reader under the "A" icon select (say) the Arial font family. Also, set the line spacing to perhaps 1.5x and margins to small.

I am not convinced that Amazon's pt sizes are correct, however this may be because I have 1.5x magnification on by default under Windows, so the mapping from Windows MobiPocket Reader font sizes to Kindle sizes may be effected by that.

When I look at such a document on my Pocket PC, I have 10 type sizes larger than "normal" and 5 smaller, for a total of 15.

I count only 10 total on Mobi for PC. According to Amazon, the Kindle has 6 total.

So, from "Normal" type size (whatever that really is) on a Kindle, there still be 3 biggers and 2 smallers? It would make sense - as long as it isn't 1 normal and 5 smaller sizes........I just want to make sure it will be big enough for dear old dad to be able to read again. :bookworm:

-bjc

I enclose screenshots of the six font sizes. The page is from HarryT's Dickens, Charles: A Tale of Two Cities (Illustrated). v2, 24 Dec 2007 (http://www.mobileread.com/forums/showthread.php?t=17594). These are actual dumps of the screen, using Alt-Shift-G see Hacking the Kindle part 3: root shell and runtime system (http://igorsk.blogspot.com/2007/12/hacking-kindle-part-3-root-shell-and.html). If the fonts look fuzzy, your web browser may be shrinking the 600x800 image - usually clicking on the image will bring up the full sized version. Note that your computer monitor may have fewer pixels per inch than the Kindle, so the image will be larger on the screen than on the actual device.

I think the line spacing should be smaller, particularly for the large fonts, but that isn't currently a user-selectable option. There is also just the one font (a bolder font, or a bold everything option, might also help readability).

It is hard to go on "standard" font sizes because fonts differ in footprint.

If you take my screenshots and print them on paper at 167 dpi (3.6" by 4.8") this is very close to what the Kindle screen looks like - except that the background is gray. The background does not effect readability much, particularly at the large font sizes.

A picture's worth a, um, er, (oh man).............
...............
..............
.............

thanks.

-bjc

I've found that even if I use 12-point for the body of the book, if the book contains any fonts bigger than about 24-points (like for the titles or chapter headers), then after I transfer to the Kindle, it uses the smallest font size when you choose either the smallest or second smallest options on the Kindle. It does start to adjust up when using the 3rd, 4th, 5th, and 6th sizes.

In other words, I used 48point fonts for the chapter headers, and 72-point font for the title. I used 12-point for the body of the book. Then, when I transferred it to the Kindle, it displayed in the 7-pt font, even when I chose the 9-point font size. Once I dropped the fonts back to 24 points for the Title and chapter headers, the problem went away.

I've found that even if I use 12-point for the body of the book, if the book contains any fonts bigger than about 24-points (like for the titles or chapter headers), then after I transfer to the Kindle, it uses the smallest font size when you choose either the smallest or second smallest options on the Kindle. It does start to adjust up when using the 3rd, 4th, 5th, and 6th sizes.

In other words, I used 48point fonts for the chapter headers, and 72-point font for the title. I used 12-point for the body of the book. Then, when I transferred it to the Kindle, it displayed in the 7-pt font, even when I chose the 9-point font size. Once I dropped the fonts back to 24 points for the Title and chapter headers, the problem went away.

Why don't you omit the font for standard <p> tags and use size="+1" for larger text? Or does mobipocket understand style="font-size:150%"?