How can I have multiple instances of a prefab using a Substance and SkinnedMeshRenderers

Hello!

I am having difficulty with an avatar system that utilizes substances. I have an editor that swaps between meshes, and manipulates substance parameters based on which mesh is chosen. All is fine until I duplicate or drag in another instance of the character prefab. When I change the sharedMesh and sharedMaterial on one instance, the other instance(s) change too. I tried changing the mesh instead of sharedMesh, but I get leaks. Using material instead of sharedMaterial doesn't work at all.

Sample code:

 //SkinnedMeshRenderer mesh = mesh I'm replacing
 //List<SkinnedMeshRenderer> meshes = other meshes
 //int index = integer;

 mesh.sharedMesh = meshes[index].sharedMesh
 var substance = (ProceduralMaterial)mesh.sharedMaterial;
 if(substance) {
     substance.SetProceduralEnum("Shirt_Color", index);
     substance.RebuildTextures();
 }

Does anyone have a solution for this issue?

Thanks!