as from the website, "Proofed European 12oz C-Canvas is great to wear and will last for ages" that would be thick cotton canvas.. i can see how they would hold up well, tho may be a bit warm for some parts of the world... oh, and they do have waterproofing in them as well according to the "care instructions" page. sounds like they could be fairly nice!
my main issue with them (other than the price) is that they don't appear to be cargo pants, which is a major factor for me having gadgets and not wanting to carry a Murse.
I wear tactical pants from 5.11, they are nice so far, dunno how indestructable tho, but they are made for police wear and tear so should be alright and have plenty of pockets for my gear!
http://511tactical.com/index.asp?dlr...2&number=74251