Ok, here is what you need to do.
There si to ways.
First Way:
Go to the render layer and press Ctrl+C when done go to the sig and make a new layer, and then Press Ctrl+V to paste it, thrn its a matter of resixing and putting were you want.
Second Way:
Since you have the sig open it is also easy, close off the render one, then go to File>Open As Layers, select the render file andopen, it will open on top of the sig on a ne layer, then its a matter of re-sizing and postioning it were you want.
