The dyeing process didn't work (the material was bright green and I was trying to make it black) but they've ended up a nice dark green colour anyway:

Needs ironing and bracing bars attaching to top and bottom, etc. but at least it will stop people from looking in whilst we're sleeping in there!
Going to try to make the centre curtain now, using this pattern:

Once they're sewn, I'll soak them in Nikwax Cotton Proof to give them a bit of protection