Very often I encounter a beautiful image with black background but with a slight set back — the background is not as “black” as the author (and I) intended to be. And again often, you can see lots of photoshop efforts to make it black, such as spotty blobs of different shades of black, traces of black brushes, etc, but these efforts fail too frequently to wonder how to get a good clean black background!
PETER Y LIN 