I am trying to make a dark rim around the uv-seams of a mesh i.e. making the seams of a cusion a little darker. Is there a way in Blender to use the uv layout and blur it a little to use it as a mask mixing two shaders?
So far I only managed to create this effect by making such a mask in photoshop. This is counterintuitive because the shader should be as procedual as possible.


Is there any way to achieve this without using self made texture?