A FIRST paragraph with no text indent and first word in smallcaps.

A plain paragraph with 1em text indent. Most paragraphs in a book will be like this one.

This paragraph has no text indent, and has a 1em gap above it. Often used to indicate a change of scene

Another plain paragraph with 1em text indent. Most paragraphs in a book will be like this one.

The default font size on the Kindle is equivalent to the CSS small text size. This sentence is explicitly small. Back to the default text size. This sentence is explicitly medium. Unfortunately, in ePub, text size medium is usually the default text size.

Kindle HTML uses the <font size="[value]"> HTML tag to set font size, and all CSS setting of font size is converted to this tag by Kindlegen. The value used in the font size tag can range from 1 to 7 in standard HTML, but Kindle HTML also uses sizes from -3 to +3. Note that size 3 is different to size +3. Despite apparant absolute and relative forms, in fact the relative form is just another way of specifying an absolute size. (But as with all Kindle font sizes, relative to the base font size chosen by the user.)

Oddly, the two ranges aren't quite the same. Size 1 is equivalent to size -2 and size 6 is equivalent to size +3. Size 7 is bigger than can be obtained using the 'relative' font sizes, and -3 is smaller than can be achieved with the 'absolute' font sizes. If the user chooses a very small or a very large base font size, some of the sizes set in the HTML don't show any difference when displayed.

This paragraph demonstrates the different sizes obtained by using the named font sizes in the font-size CSS attribute. xx-small text x-small text small text medium text large text x-large text xx-large text

This paragraph demonstrates the different sizes obtained by using percentages for the sizes in the font-size CSS attribute. Experiment has determined the boundaries at which Kindlegen 1.1 generates different font sizes. 52% and below: tiniest text -3. 67% to 53%: tinier text -2. 88% to 68%: tiny text -1. 114% to 89%: default text 147% to 115%: big text +1. 193% to 148%: bigger text +2. 194% and above: biggest text +3.

Unfortunately, Kindlegen also translates the larger and smaller CSS text-size properties into <font size="[value]"> tags, +1 and -1 respectively.

Unfortunately, Kindlegen also translates the larger and smaller CSS text-size properties into <font size="[value]"> tags, +1 and -1 respectively.

If you want font sizes that are truely relative to the current font size set in the HTML, it's necessary to put the <big> and <small> tags directly into your XHTML.

If you want font sizes that are truely relative to the current font size set in the HTML, it's necessary to put the <big> and <small> tags directly into your XHTML.

Using <small> and <big> explicit tags in addition to the CSS can generate an even larger range of font sizes, but they only display differently if the base font chosen on the Kindle by the users allows it.

This is 50% text smaller smaller2 smaller3 smaller4

This is xx-large bigger bigger2 bigger3 bigger4

SMALLCAPS CAN be simulated well by using capital letters scaled down by two font sizes.

This paragraph is in 80% text size, one step down from normal text size on the Kindle. For SMALLCAPS to look good in smaller text, it's necessary to use even smaller SMALLCAPS.

Because all ways of specifying font size in CSS generate 'absolute' font sizes on the Kindle, we won't get the same result on ePub as on Kindle if we specify font sizes in CSS as percentages, or ems. This is because in ePub the relative font size is relative to the curent font size of the text, not the base font dsize chosen by the user.

An added complication is that for the Kindle the default font size is 3 (small) but on ADE and most or all other ePub renderers it's 4 (medium). This means that specifying absolute font sizes will also have different effects on Kindle as on ePub.

It's safe to use percentage font sizes if in text of the defaut size. But that's the only case. It seems likely that consist font size use can only really be obtained by using different CSS style sheets for ePub and Kindle.

It would be possible to obtain consistant effects by only using the in-line tags <small> and <big> in the XHTML. But this is an ugly solution.