Arthur Price of England Sovereign Silver Plate. The very best and most luxurious silver plate cutlery on the market, with a silver thickness of up to 40 microns. Unconditionally guaranteed for life and will offer a richness of patination, in time, that is beyond compare. Dishwasher Safe. The Harley pattern originated from the Art Deco period of the 1920s and 1930s which demanded bold geometric design and a strong emphasis in quality.