Thick/opaque net curtains

[BloomedAgain]

What fabric should I be looking for? I need to make privacy curtains for a bedroom window which is on a busy street (perfect height for passersby to peek). I would like to let some light in but for the curtains to be quite opaque. Should I get a linen or voile fabric or similar? I think most nets are too transparent?

Have you thought about window films? Easy to apply, easy to get off, and in my experience nobody can see in but it's let through a fair amount of light.

Thanks Grumpy I'm thinking about that too. It's a massive window so was thinking about using my newly learned sewing skills.