When I was a commune member in the '70s, I did some interior trim, and left a subsequently invisible graffito on each layer:

One thing I do whene'er I can
Is fuck up sheets of Deciban.

But when there's none of that to do,
I'll fuck up sheets of wallboard, too.

There's lots of that. But when there ain't,
I'm always glad to fuck up paint.

And now it's ready to move in.
My fuckups end, and yours begin.