what means double-layer curtain wall ?
On the plus side you want a feature wall. On the minus side your solution is pretty expensive, particularly if you aren't staying that long. OK you can take it with you but you've got the hassle of taking it all down and making good where the curtain rod fixings were. It's cheaper and easier to do a feature wall just using emulsion paint in a single colour such as red/burgundy or maybe a chocolate. You can turn it back to cream for the price of another tin of paint and a brush and keep your landlord happy so you get your deposit back.
If you mean a double-layered wall curtain, that means there are two sets of curtains that go on top of each other over a window. Hope this helped! and if it didn't send me a message and I'll try to do my best!
