New material only covering the same area as the previous one

Hi,
so I'm trying to add a simple outline over the whole model but it covers instead only the area that the previous material did. Example(pictures added because I'm really bad at explaining) : So I have this skinned mesh renderer(automatically generated after importing from .blender) with those values under "Materials" ![3 materials with the last one named black][1] When I increase the "Size" to 4 and add my outline material to the fourth field ![4 elements with the last one named outer][2] the "outer" material covers only the area that the "black" material covered.
I'm thinking that this is probably not the way I should add materials ... how can I set it to cover the whole model? Thanks in advance
EDIT:
Ok now I realize my fault ... instead of applying the outline shader directly to a material (eg "black") I created a new empty material -> applied the shader on it -> tried to add new material without the need to. I'm still kinda curious though, can I add two materials in one mesh? and how do I specify the mesh? [1]: http://i.imgur.com/SZMwPWA.png [2]: http://i.imgur.com/JPj0fB1.png