These are covered bread pans with a sliding cover that can be shut during baking. This will keep the bread in a uniform rectangular shape (and perfectly square slices) with no rounded top typical of most baked bread loaves. The dough used is typically a low crumbing type of yeast bread. Pain de Mie comes from the French “pain” for bread, “mie” for crumb. These baked bread loaves are useful for making tea sandwiches of varying shape or toasts for canapés, where the slicing is done horizontally across the length of the loaf rather than individual vertical slices. Doing it this way ensures less trim loss when making quantity sandwiches or canapés. Also, they are made for making regular sandwiches with a uniform square shape.