Argentium is a special type of sterling silver with more silver content (93%), less copper content, and 1/2% Germanium. Germanium is a rare earth metal that provides a CLEAR layer of oxidation on the silver. This means your silver is hard and strong like sterling (as opposed to fine silver) but does not 'tarnish.' Or, if it does tarnish it takes a very long time to occur. I've had samples sitting in the open air of my coastal atelier for over 6 months with zero hint of tarnishing. This is not an advertisement for Argentium - just wanted to explain the material. To the point... I recently received a commission for a piece of Argentium silver guilloche' work by Roni Weiss (http://roniweissjudaica.com/). This piece is very large by guilloche' standards and the engraving is very deep - about 2.5x as deep as I have ever engraved before. Check it out. I just may have to do more of this type of work!