Originally Posted by murg
I was playing around formatting an epub today, and formally discovered what may be a bug in the line spacing adjustments in the font adjustments on the reading screen.
I've been seeing this behaviour for a long, long time, just never got to the point were I could test it. I think it is happening on both the Glo and the Touch (and probably the Mini).
The css element line-height controls the line spacing.
It looks like the smallest line spacing that Kobo allows you to set on the font adjustment screen is about 125%. It will gladly increase the line spacing above this value.
A line-height of 100% is a more natural setting.
In any case, the line spacing slider should have 100% in the middle, allowing you to have larger or smaller line spacing than 'normal'.
If the line-height is set in an epub's css, then the line spacing adjustment is disregarded. This is why setting line-height in the file's css is not a real solution.
The above was determined using Amasis on a Glo with a side-loaded book.
That is on the Glo, Touch and Mini. Personally, I use the stylesheet to set line height to my preference of 1.2 which is below the minimum of 1.35 the slider will set. I do the same with margins and simply leave the line spacing and margin sliders at their minimum settings unless I am reading a kepub or library book where I don't have the option of editing the ebook.
I'd disagree that a line height of 1.0 is natural unless you are fond of ascenders and descenders meeting.