3d Printing Advice?

Hey guys

Buddy of mine wants a simple 3d model creating of this shape ready for printing. I’ve never modelled anything for 3d printing before and would like some advice please. I can create the basic shape well enough but the letters are a point of unknown for me. Ultimately this is gonna be for some kind of necklace so would modelling the letters separately and simply placing them on top work well enough? Or would engraving the letters INTO the model work better?

For rings, the engraving is cut into the piece. For pendants, if it’s a name plate style, you’d see the letters popping out. Unless, the letters are used to imprint metal purity and that’s something you’d place on the back of the piece and it is engraved into the metal like it’s done for rings. Don’t go deeper or thinner than 0.5 mm or they won’t come out during casting.