Map grids The final commonality you can use in a diagram is an old-fashioned map grid. Back when maps were printed on paper, they had grids to help you find a place (“If you’re on page 29, Market street is at F-6.”) As diagrams increase in complexity, a map grid can help people focus on the right part of the diagram. This is most useful as diagrams get bigger, more detailed, or both. (7/9)