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. Royal Pearl was first introduced in 1990 to celebrate H.R.H. Queen Elizabeth, The Queen Mother's 90th birthday and reflected her love of pearls.