This is a piece of used vintage cotton fabric (once a curtain panel or maybe a tablecloth?), does have some spots / discoloration. It's soft, thick fabric without any fading, has a wonderfully retro floral print!
This measures 52" wide (no selvages), 1 1/2 yards long. I have not washed or soaked this at all, and I'd expect that it would be helped with a good wash. The bold pattern and colors make the spots a little hard to see as it is!