I have made a cornice out of styrofoam molding. Used "wall molding" as it was the most suitable I found.
It will be placed above our curtains in the living room (about 4m long and extends about 25cm from the wall).
Since the styrofoam doesn't weigh much, I think 4 brackets should be enough.
However, I don't know where to buy such in the right dimensions, so I guess I have to make my own.
I was thinking of something according to this sketch I've made:
I don't have many tools for working with metal. Hacksaw, hammer, metal drill... that's basically what I have.
Where do you think I can buy the metal? Do you think aluminum would work, so it will be easy to bend?
Are there ready-made ones or should I make them myself?