Whenever I've made whole wheat bread, the dense whole wheat flour makes for a very dense loaf of bread, so I've got to mix it with something like bread or AP flour.

My wife is big on 100% whole wheat bread.  When she buys it, it's got to say specifically "100% whole wheat".  But I'm trying to figure out what that means.  When we buy the cheap store brand of 100% whole wheat bread, it's light and spongey like Wonder white bread. Is it really made with no flour other than whole wheat flour?