the margin between the <#pane=panes> of a <#sheet> of <#stamp=stamps>. The gutters of mid-20th century sheets may contain markings such as dashes or crosses that aid in <#perf=perforation>. The gutters of modern sheets, containing more than the traditional four panes, may contain other <#marginmark=marginal markings>, including <#pn=plate numbers>. The <#margin> around the outside edge of the sheet is not a gutter. Gutters are only found between panes.