IMO, the heat of the DW is the culprit. So it’s not “us”.
Even a Sani-Tuff will warp in the DW. Epicurian says theirs are “DW-safe”, but I doubt it means they won’t warp. The only boards I’m aware of that claim no warping (up to 350F) is Tuff-Cut. http://www.webstaurantstore.com/san-jamar-tc121812-12-x-18-x-1-2-tuff-cut-cutting-board/511TC121812.html
