All of my handprint pieces are made from fine silver and all findings (ie, cufflink mechanisms, bracelets, necklace chains etc.) are made from sterling silver.
The difference between fine silver and sterling silver is that fine silver is 99.9% pure silver. Sterling is 92.5% silver with the remaining 7.5% composed of other metals, usually copper.
They look the same, wear and polish the same, but fine silver is more "pure" and is, therefore, more costly and often considered more desirable than sterling. Fine silver also uses recycled silver, so it is eco-friendly too!