

What the hell is a pixel? - chrisfarms
http://maybeuseful.ghost.io/what-the-hell-is-a-pixel/

======
PhrosTT
What is the current 'proper' way to do text sizing in CSS? %?, px?, em?, rem?

I swear it changes everytime I look.

~~~
jeremysmyth
This depends entirely on the element you're sizing, the text it contains, and
its relationship to the page.

In short, _design_. You use the tools available to achieve the best designed
results.

For example, things measured in characters:

\- the human eye finds it easier to read large blocks of text that are
approximately 60 characters wide

\- First-character indent makes more sense in terms of ems than pixels if your
site's font size is ever going to change (which flexibility is the whole point
of CSS, right?), as does inter-paragraph spacing and other design elements

Things measured in pixels:

\- Device screens often have a fixed width that's measured in pixels

\- Images have a defined size (although you may wish to scale this)

\- In conjunction with the above points you may wish to size a paragraph to
fit some other page element and the device's screen, or even size a single
character at the start of a piece.

...and of course for very specific applications you may wish to size things in
physical units such as cm or inches.

