Overprint Fill is a setting in most graphic design programs used to tell a printer when one graphic design element should print “over” another graphic element. Some graphic design programs, such as Adobe InDesign or Illustrator, set 100% Black to overprint by default. It’s assumed that 100% black will be used for black text and in most instances, should overprint. Overprint Fill can become a problem, when 100% black is used for design elements set over other elements or when light-colored text/graphics, that sit over a darker color, are inadvertently set to overprint. Graphic elements inadvertently set to overprint fill may appear correct in the digital file or eproof, but will appear different when printed.