La Farge 's patent focused more on the material and Tiffany 's more on its use in construction .
It appeared that the two patents might be mutually dependent , prohibiting either artist from making stained - glass windows without the other 's permission .
Since La Farge 's patent focused more on the material and Tiffany 's more on its use in construction , it appeared that the two patents might be mutually dependent , prohibiting either artist from making stained - glass windows without the other 's permission .