I just googled Dugast a bit and found two places that discuss the Dugast 30mm.
A french-canadian shop has a site:
http://www.thecyclery.ca/dugast/ -- they say 110 lbs and under for the 30's! and 187 lbs and up for the 32's! (they also tell how to remove tread from a casing!) -- anyway, calling out IDEAL BODYWEIGHT for tires fits with my impression.
Here's a forum w a bunch of CX tire reviews. The guy says he loves the Dugast 30 for mud. But he doesn't say how much he weighs.
Cross tire review | Ridemonkey Forums