Is this chain solid silver or silver plated?

It is solid 925 sterling silver with rhodium electroplating on top. The rhodium adds a bright white finish and slows tarnishing, but the metal underneath is sterling silver throughout.

Which width should I choose?

The 0.5mm and 0.6mm widths read as very fine, near-invisible chains best for layering or small pendants. The 0.7mm is still slim but holds up better as a standalone collar.

Will a pendant fit on this chain?

The anchor links are small, so only pendants with a fine bail will slide on. For most pendants, use a separate jump ring or choose a wider chain.

How should I care for it?

Keep it away from perfume, chlorine and sweat, wipe it with a soft cloth, and store it dry in a sealed bag. Avoid pulling or tugging on the fine links.

Is 16 or 18 inches better for me?

16 inches sits at the base of the neck as a collar; 18 inches rests lower on the collarbone. Choose based on where you want the chain to fall and what you plan to layer it with.