Florescent lights can also cause damage. I used to have a work room in the basement when I did bed ruffles for a designer. The lights were on much of the time. They faded a signed Linda Stokes print that was given to me. I was just sick about it when I realized what had happened. I don't know if any fabric was affected because it was not left out for long, but my machine was definitely yellowed. I think fabric left on a design wall or stored on open shelving could be in harm's way.