11x17 is incredibly common too. Usually it is oriented landscape and z folded to get a large diagram into a document. It's kind of irritating that the most typical large format size is 24x36, which is a different aspect ratio than 11x17, for a variety of reasons. If you're designing something you need to know what aspect ratio to design for. Most copiers can do 11x17, and if the standard large format size was 22x34 it would be exceedingly easy for most offices to produce good working copies of large documents. Best compromise I've seen is when people put a logo or header on the side that can be omitted when you switch aspect ratios.