How to generate a font-weight:100; equivalent?

Hello, I’ve a weight problem

As the options for the effective weights in are:

250 / thin, extralight, ultralight
300 / light
400 / regular, normal
500 / medium
600 / demibold, semibold
700 / bold
800 / ultrabold, extrabold
900 / black, heavy

I was wondering how to set an instance with a weight of 100, or 200?
As used in CSS with font-weight:100;

There are some problems with wight class settings below 250 (on some windows machines, the rendering will be to fat).

If you still like to use 100, use the custom parameter openTypeOS2WeightClass.

great, that helps!