Doing a mask layer to reveal a pixel layer underneath it, but black is revealing and white is concealing.

[Joss Pittman]

I don't know why my software is doing the opposite of what I was told. I thought black conceals, white reveals. Somehow it's doing the opposite, where black is revealing and white is concealing. 

[smadell]

Black is “revealing” the pixel layer underneath because it conceals the layer to which the mask is attached. That’s what it’s supposed to do!

[Joss Pittman]

19 hours ago, smadell said:

Black is “revealing” the pixel layer underneath because it conceals the layer to which the mask is attached. That’s what it’s supposed to do!

I'm confused. I have a image of a shark under a black pixel layer. When I create a mask on the black pixel layer and apply the paint brush tool using the black color, it reveals the shark, but white just reapplies the black pixel layer. 

[Joss Pittman]

I greatly apologize. I thought the black concealed the layers under the pixel layer. I now realize it conceals the layer the mask is applied to, thus revealing what's underneath it. 

[smadell]

No need to apologize at all! Masks are tough to conceptualize. Here's a few suggestions. (1) If you want a cut-out photo on a background (like a shark on an otherwise black background) put the shark on top and attach the mask to the shark layer. (2) Instead of a black Pixel layer, put a black Fill Layer on the bottom instead. A Fill Layer is basically a vector object, and takes much less "overhead" to compute. Instead of putting millions of individual black pixels down there, just tell the layer to fill itself with a single color.

Here's a sample of the layer structure you might want to consider: