Noticeable throughout the caseback, the oscillating mass of the movement is delicately engraved. It can be produced from 18-karat gold and decorated by hand by using a barley grain pattern, performed by guilloche In case your Omega has the words and phrases 'Grasp Chronometer' within the dial—as is viewed inside https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/