The tin layer on tinned wire protects the copper core from oxidising and accepts solder with minimal cleaning. Silver coloured and will accept patina. Use as reinforcement in suncatchers, to make jump rings and for applying quick and easy decoration to your soldering. Sold in one pound spools. 18 gauge wire is thin enough to use as decorative elements. It's also strong enough to be used as jump rings or reinforcement in small projects like suncatchers. 18 ga measures 0.1cm diameter. 1 pound spool.