I see what you mean.
I actually use relative font sizes when I can. The only times I use absolute sizes is when I need a font to match the size of an image. Usually it is a BIG font. (what do you do when you need a font size bigger than xx-large?)
I said to use points to make the text a certain size on the monitor, regardless of settings and resolution.
I don't know of anything other than percent that changes with the size of the window. And then, it works horizontally, but not vertically.
I learned something today. There is confusion among authors of CSS materials, because "em" has two different definitions:
- The typesetter's em is the WIDTH of the capital M. It varies with the style of the font. No relative measure was needed for typesetting. The em was used to figure how much text fits on a line.
- The real CSS em is the HEIGHT of the capital M. It is equal to the font size in points.
Unfortunately, the author of the book I learned CSS from looked up em in a dictionary, and used that definition in the book.
The typesetter's em is useless for sizing other items to fonts. It is smaller with a narrower font. Thus, I was misled into believing that the CSS em was useless.
The real CSS em looks very useful. I am going to start using it, now that I know it is not the typesetter's em.
So it seems we have four different things to refer sizes to:
px - the size of the pixel. This depends on the monitor resolution
in, pt - absolute size, assuming a normal size monitor
em - the actual displayed size of the font
% - the size of the container
I normally use percent for the sizes of box objects.
I use inches and points when I need to present a picture and size other objects to it. I do this for the purpose of making sure the detail of the picture is always large enough to be visible.
The only thing I use pixels for is to make sure a border is always visible, but is as small as possible.
I was using points for padding sizes (to separate text from borders), for lack of nothing better. The em is a better measure, now that I know it does not vary with font style.