Document wordspace better

[wspr]

Paraphrased from the XeTeX mailing list:

Is it possible to set different interword space for different font sizes? E.g., SizeFeatures={ {Size=-10,WordSpace={20,1,1}}, {Size=10-,WordSpace={1.1,1,1}} }

I am afraid that this is a limitation in LaTeX's font selection mechanism (although not in TeX itself).

If you need to change the inter-word space locally, you can use the \spaceskip and \xspaceskip commands (see TeX by Topic §20.3).