Since I have been using Azo, I have noticed that the paper actually does seem significantly sharper than enlarging papers. And I don't mean maybe sharper, or sharper with a certain kind of print in a certain kind of light. I mean that when I compare my azo contacts to contacts done on enlarging paper, the azo really looks a whole lot sharper.

Why? I assume it's some kind of optical illusion. Is it because the blacks are much blacker? Local contrast greater? Some kind of edge effects?