7. The Menus / 7.3 Functions in the View Menu
f there are layers in a document that extend beyond the document borders, then these exceeding parts are normally displayed with a reduced intensity. This is done by painting the border color (see chapter 7.10.1.26) with 50% intensity over the border.
By activating Hide Border Content, the border color is applied with full intensity. If the border color is opaque, the exceeding parts are no longer visible.