In order to change any element of the invoice on the printout, go to the Settings> Account settings> Print settings tab, and then at the bottom of the page fill in the field Customize print with CSS  with an appropriate CSS code.

To change column widths use this code: } @media all{  thead :nth-child(0n+5){  width:30% !important;  }  } 

Note! Please remember that the following changes are visible only on the printout or in the PDF generated from the system.