Oomis, are you referring to the engagement ring, or wedding band (kiddushin ring)?”
Kiddushin. After the chuppah, the ring may be engraved and cut through and through, to whatever extent desired. Before the chuppah, I remember the rabbonim examining the ring to be sure there were no holes going through it. I did not understand why, but they said it has to be solid for the harei aht part.