I've used my Ramelson's for relief carving, and you can do most of it with the basic set, but there are some areas that bent blades are useful. My set has three bent blades in it, perhaps I was lucky in finding a set (12) that covers both round and relief carving, but there are still bent blades that I needed.
This web page is for a set that are dedicated to relief carving and small detailed stuff at that.
http://www.traditionalwoodworker.com...oducts_id=1486 You will note, they are expensive, but I tell you....they are a delight to use!!! :-) The handles are shaped perfectly for relief and the steel is excellent.....the come in need of a good final hone and a couple I had to use stones on to shape better, but they hold an edge great and have some super profiles. They make detailing a breeze. I found them to be a good investment.
Bob