In their specs for the City College campus in upper Manhattan, George B. Post & Sons called for such a finish on the white terra cotta trim around the dark Manhattan schist field.  That might have indicated that he didn't want a glazed look, because he wanted it to appear like stone, perhaps limestone.

 

Would a "sand blast finish" have indicated simply a rougher surface of the terra cotta before firing?  Or would that indicate actually sand blasting after the firing?

 

 

Christopher