Engraving fails in two directions. Either the text is too long, in which case it is illegibly small and reads as a smudge, or it is too public, in which case you are explaining it for the life of the piece. The safest position is the inside. Inside a band, inside a signet, on the reverse of a pendant or a locket, on the inner face of a cuff. A hidden inscription can be as sentimental as you like because nobody is reading it over dinner. An external inscription needs to survive being read by strangers, which rules out most of what people want to say. On length, a date, a set of initials, a single word or a very short phrase is the practical limit on most pieces, and a jeweller will tell you the character count for the specific surface. Take that number seriously rather than negotiating it, because the compromise is always a smaller typeface and a smaller typeface is what disappears after a year of wear.

There are two methods worth knowing. Machine engraving is precise, shallow and inexpensive, and it is the right choice for the inside of a ring. Hand engraving is deeper, has visible variation, costs considerably more, and is what you want on a surface that will be touched constantly. Depth is the variable that decides longevity. A shallow inscription on the outside of a ring you wear daily will soften within a few years and vanish within a decade, because rings are polished by hands and pockets whether you like it or not. Inside surfaces wear far more slowly. Metal matters too. Silver is soft and takes engraving beautifully and loses it fastest. Gold at a lower karat is harder and holds a line longer. Also worth knowing that engraving usually removes the option of resizing a ring, since resizing cuts the band exactly where the text tends to sit. If you might resize, engrave a different piece.

Engrave the date rather than the sentence. Almost everyone who engraves a phrase finds it a great deal more embarrassing at year five than at week one, and the date carries the same information without the tone. Put it inside. Pay for hand engraving only if the piece will be handled, otherwise machine work inside a band is invisible anyway and the money is better spent on the piece. Do not engrave a plated item, because the engraving cuts through the plating and exposes the base metal along every line. And decide about sizing first, since an engraved band is much harder to alter later. If you are engraving a gift, initials and a year are almost impossible to regret. If you take one thing away, engrave the inside, because an inscription nobody else reads is the only kind you will still like in ten years.