Enamel through a process that will take eighty hrs. It comes in eighteen-karat white gold with numerous shades of eco-friendly or in 18-karat pink gold with blue hues, equally accented with diamonds. The bottom metallic of each is initially sealed that has a clear enamel then layers of opaque white https://www.watchesworld.com/from-sean-to-daniel-tracing-the-evolution-of-james-bonds-iconic-watch-collection/