Window art in World War 1.

During the second world war, Parisian shop owners would place lines of tape across their windows to avoid flying glass in case of a nearby bombing or explosion.

It turned into something of a design contest as they started creating patterns on their shops.

Images can be found on the National Library of France's website. I've posted a few below.

Photo of paris shop window with tape art on it.
Photo of paris shop window with tape art on it.
Photo of paris shop window with tape art on it.