My nephew asked why I tape the inside corners of my fort and I had to stop and think about it
He watched me build a tunnel fort in his garage on Saturday and asked why I run a strip of tape on the inside of every corner joint instead of the outside, and I didn't have a real answer until I was driving home, which is that outside tape looks fine but inside tape is what keeps the panels from folding in when a 6 year old leans on the wall.