Elm is super strong in tension, so-so to weak in compression. You can leave the belly natural and trap the back, or you can toast the belly as Pat said and go a little more narrow. I love working with elm and shooting elm bows. It just lends itself well to my default design tendencies and shooting style. Elm performs very well in any highly strained design, esp with belly well-toasted. That said, I'm doing an elm ELB type bow that's not really highly strained, but will need a good toasting. I've heard well-toasted elm is very yewish.