I have created a layer and copied it to a new layer. I want the copied layer to completley cover the eixisintg layer but it won't move right to the edges, it leaves an outline of the previous layer. How can I get it to completelety cover the layer?
Could you please post a screenshot with the Layers Panel visible?
It seems likely that the edges are soft/anti-aliased.
Naturally a X% transparent pixel atop another X% transparent pixel will result in a mixture of those (and the underlying pixel).