Years ago I left a drawing - on paper - in the spare bedroom; the sunlight quickly discoloured the paper. If it had been consistent, it wouldn't have mattered too much except that part of the drawing had been covered at an angle.

The room I chose at our new place is long and skinny with windows at one end and a large closet at the opposite end. The closet does not have a door and I have wondered about creating a sliding door that would also be my design wall at the same time. Then I would have no light penetration. You can have fading from electric light as well as sunlight.

Looking back I see others have mentioned fading from interior lights.

My sewing room now has a special shade my son got for me, works perfecr for the one large window! It’s the brightest room in the house! Well, not anymore and no faded fabric!