Wandering around IKEA the other day I found some roller blind used for room darkening. They're very flexible, thin(.65mm) and opaque.
The blinds are available in different widths X 77", three colors, white, black and gray.
They seem to work OK for light proofing a room and the catalog # is"tuppler"
A second thing I spotted was a hanger, for what I dunno but it hangs from a ceiling has eight arms and two spring clips on each arms and is about 12-13" in diameter.