A little trick I learned after running out of Bounty paper towels in
half-sheets (Select-A-Size). Take a regular Bounty full sheet, turn
it 90 degrees, then tear in half. Do this very accurately and quickly
and you will get half sheets. Not exact matching sheets, but close
enough. Make sure you are tearing exactly in the middle of the whole
sheet. The faster you tear, the better.

nb