I am stacking .png images to create a 3D effect. I was wondering how I could set certain pixels to be transparent or see through. I want you to be able to see a picture that is behind another if the first picture is "empty". I have used a tool to set all the pixels I want to be see through to black (0,0,0) and I was wondering if there was a tool that would allow me to change all pixels that were equal to this value to transparent or see through.
Thanks! Hopefully this is clear (no pun intended), this is my first time posting and I'm new to photo editing.