Maybe the title is hard to understand so I explain quickly. I have 2 layers, one with a flat text and the other one with the outline of the text (freestyle). If I combine both (with Alpha Over) the resulting image is not the same as if I render on the same layer text plus the contour. It seems like the outline is less "strong" when I'm combining the layers in comparison with a direct render of object + contour.
As it can be seen on the image (on a subtle way) on the combination between layers, the stroke is a little bit less strong as the full render. How do I do to get exactly the same result as the full render when I combine two layers?