I have a pair of Obsidian Foundry pants that no longer fit (I lost weight). They're new with tags. The color is Conifer and size is 34x32. $160 TYD PayPal F&F
Cannot comment on medium or large obsidian's, but I own a pair of medium Corrugate's. With the elastic waist of the Corrugates, I would say they're the same size with the waist fully extended on the Corrugates.