Noticed recently: Japanese washi tape used as a decorative device.

Above Pink washi tape adds a dash of color to an otherwise gray tableau; via Cherry Blossom World.

Above L: Image via Madame Stoltz. Above R: Image via Cherry Blossom World.

Above: Photographs affixed to the wall, via Annaleena's Hem.

Above: A painted wall outlined in washi tape, via Hanna's Room.

Above: A decorative tableau via Cherry Blossom World.