Gold-filled is made by heat- and pressure-bonding a thin layer of 14 karat Gold or rose Gold to a Brass (or other base metal) core. The solid Gold overlay covers the brass surface, making it tarnish-resistant.
This finish is great for everyday wear but not recommended for people with metal allergies. You can keep your jewelry when you shower (or wash your hands) but it's preferable to remove for a longer dip.
Flesch uses Gold-filled material since 2016 and the quality of this finish keeps surprise and please customers. It's really a great option for gold and rose gold jewelry if you are not ready yet to dive into solid gold.
However, due to the nature of the material, gold-filled jewelry cannot be polished and might present a somewhat less reflective surface than solid metal. We always take good care to deliver only the nicest pieces, so no one really can tell!