font-weight on Windows

Question

I've the following code:

p{
font-family: Helvetica, Arial, sans-serif;
font-weight:100;}

It works on Mac OSX on Safari and Firefox, but the font-weight don't work on Windows in any browser. Why? How can I solve that?

Answer 1

From the Mozilla Developer Network CSS docs for font-weight:

"If the exact weight given is unavailable, then 600-900 use the closest available darker weight (or, if there is none, the closest available lighter weight), and 100-500 use the closest available lighter weight (or, if there is none, the closest available darker weight). This means that for fonts that provide only normal and bold, 100-500 are normal, and 600-900 are bold."

You don't see a lighter weight on Windows because there isn't one for Arial, so it falls back on a normal weight instead.

Answer 2

According to a comment at the Sitepoint CSS reference page for font-weight there are at least IE issues on Windows:

I would argue that none of the browsers listed support font-weight to a 'full' standard, as none support the numerical scale. Currently only Firefox 3 and Webkit nightlies support numbers as values of font-weight.

Now that comment is a 2 1/2 years old so it may not be applicable today.

I would recommend trying to set the value to "lighter" and see what happens.