The four decisions that matter most are width, length, solid versus hollow construction, and intended use. Width determines visual weight and style impact. Length determines where the chain rests on your body. Construction determines durability and long-term value. Intended use — pendant chain, statement piece, or layering chain — drives all the other decisions.
For pendant use, prioritize a solid chain at a width that fits through the pendant bail — typically 3–5mm covers most pendants. For a standalone statement piece, solid construction at 5mm and above gives the chain enough visual weight. For layering, a 2–3mm chain at a distinct length from your other chains works best.
Always confirm the chain is stamped 14K or 585 and made in Italy for quality assurance. Buy from a retailer who provides a certificate of authenticity. If uncertain between two widths, size up — a chain with slightly more presence always looks more intentional than one that reads as too delicate for the outfit.