Opus interrasile comes from the Latin opus (=work) and interrasile (= openings). It is a metalworking technique that involves creating a style of openwork decoration by piercing a sheet of metal with a chisel or other sharp tool. The style came into fashion during the Etruscan period and was further developed by Roman goldsmiths. The style continued to flourish in Byzantine jewelry.
Usually applied as a background for an item, opus interrasile can be so finely pierced that the remaining gold strikes us as a web of ultra thin gold wires.