For your ease, let me tell you that I am not a total newbie. I have been using Photoshop for a while now and I know how things work.
Here's the problem: I am trying to use brush tool on mask. You see how we can mask out stuff by painting black on the mask layer? I am trying to do that but, brush tool doesn't seem to respond when I am painting black on the mask. It is responding when I am painting white, so it is revealing the picture behind it when I am painting it white. But, black doesn't work for some reason. I tried using pencil tool instead of brush, that works fine too. But I need feathery mask out which I can only get with a brush tool
So, any idea what's going on? Thanks a lot for reading.
Here's the problem: I am trying to use brush tool on mask. You see how we can mask out stuff by painting black on the mask layer? I am trying to do that but, brush tool doesn't seem to respond when I am painting black on the mask. It is responding when I am painting white, so it is revealing the picture behind it when I am painting it white. But, black doesn't work for some reason. I tried using pencil tool instead of brush, that works fine too. But I need feathery mask out which I can only get with a brush tool

So, any idea what's going on? Thanks a lot for reading.