Setting print area for entire workbook

[scru_ball]

I need to set the print area for every sheet in the workbook. When I tried
grouping the sheets first, my option to set the print area was disabled. Any
ideas?

 

[scru_ball]

I have 20 different workbooks each with 26 different worksheets so I would
like to find a way not to select each one individually. When I try to select
all sheets in a workbook, the option to set print area is grayed out.