Old Catalogue Cards

I love this idea.
I’ve seen old catalogue cards used to make Christmas wreaths but this idea intrigues me too.

Picture used with permission: Habeas Brulee’s photostream.
I wonder if the cards create a dappled effect through the rod holes on the walls and floor?
Anyway, if the building budget cut out blinds or curtains or you need privacy in some room, here’s a cheap and cheerful craft project for you!
Now what would be the correct LC or Dewey range for the cards?
Stephen