When it comes to the font rendering on the Web, the designer cannot do much. For example, how the font looks on the screen. For the most part, it depends on the operating systems, browsers, typefaces’ design, font files, and on whether these files are supplemented by the instructions for the most unexpected scenarios of the rendering. But sometimes the CSS properties can affect how the font looks like.
Note: the screenshots shows the font rendering in Safari 5 on MakOsi 10.6.
Slight changes of the font size can greatly affect the appearance of the typeface
First of all, there is the property of font size. Rasterization of vector contours for the font sizes that adequate to the modern screens means that each letter is represented by only the handful of pixels. Therefore, a small difference in the font size can greatly affect the appearance of the typeface.