sealing an oxidized silver ringq
 

I am oxidizing a silver ring so that it looks black. The problem is
the oxidization wears off after time especially since it is a ring. I
am using liver of sulphur to oxidize the silver. Does anyone know of
a different process or some sort of seal that would keep the
oxidization on the ring longer. I have heard of using clean nail
polish but it makes the pieces shiny which i would like to avoid.

Thank you,
hb