RP media is fine porcelain media with specific gravity 2.91, while
have no included abrasive inside the recipe, can develop extremely good
surface finishes amd produce no wearing. Because it is non-abrasive it
brightens the surface of most metals. Work hardening materials may not
brighten like non-work hardening alloys. 

Procelain with no included abrasive is long wearing, can developed extremely good surface finishes and produces very little wear. 

While procelain is an ingredient in some of the cutting media, it non-abrasive can brightens the surface of most metals