I am considering of creating a semi-permanent darkroom arrangement and it involves having some kind of material that is soft/flexible that will block-out light.

To be little more precise, my dry side will be a room that is near a bathroom. The window in this room needs to be blocked out. From there, exit the door and on the way to bathroom, there are one opening (no door) that leads to my living room. This opening needs to be blocked-out.

I know there is a such thing as darkroom curtain made specially for this purpose but they are quite expensive. Are there any material suitable for this type of use that's not quite that costly?

The window in my bedroom can be more-less permanently blocked out, so using a cardboard and tape it to the place is an option. However, the opening to the living room must be easy to operate and not-that-ugly.

Thank you.