There's a substantial dent (bordering on being a deep crack/hole) in the middle of a 3 square meter piece of painted plasterboard. I need to repair it with something durable as it's in a prominent place and thus am not sure plaster will suffice. On-top of that it will need to be painted. What should I use?
I would paint it with a flat latex paint. That will help hide some of your mistakes. Good luck!