Hide the Header and Footer Areas
Simply double-click outside either the header or footer area.
Printers have a non-printing margin, normally between 5mm and 10mm from the edge of the paper. Setting a Header or Footer to be less than the non-printing margin causes it to disappear or print only the upper or lower part of the line. On InkJet printers the lower non-printing margin can be as high as 20mm.