This is font-size xx-small
This is font-size x-small
This is font-size small
This is font-size medium
This is font-size large
This is font-size x-large
This is font-size xx-large
This is font-sizexx-small
This is font-sizex-small
This is font-sizesmall
This is font-sizemedium
This is font-sizelarge
This is font-sizex-large
This is font-sizexx-large
Absolute and relative values are easy.
However, there's a lot
to be said for
the convenience of percentages.
1/2 inch
1 centimeter
25 millimeters
35 pixels
2 exes
2 ems