Among the products Boulton sought to make in his new facility were sterling silver plate for those able to afford it, and Sheffield plate, silver-plated copper, for those less well off. Boulton and his father had long made small silver items, but there is no record of large items in either silver or Sheffield plate being made in Birmingham before Boulton did so. To make items such as candlesticks more cheaply than the London competition, the firm made many items out of thin, die-stamped sections, which were shaped and joined together. One impediment to Boulton's work was the lack of an assay office in Birmingham. The silver toys long made by the family firm were generally too light to require assaying, but silver plate had to be sent over to the nearest assay office, at Chester, to be assayed and hallmarked, with the attendant risks of damage and loss. Alternatively they could be sent to London, but this exposed them to the risk of being copied by competitors. Boulton wrote in 1771, "I am very desirous of becoming a great silversmith, yet I am determined not to take up that branch in the large way I intended, unless powers can be obtained to have a marking hall office at Birmingham." Boulton petitioned Parliament for the establishment of an assay office in Birmingham. Though the petition was bitterly opposed by London goldsmiths, he was successful in getting Parliament to pass an act establishing assay offices in Birmingham and Sheffield, whose silversmiths had faced similar difficulties in transporting their wares. The silver business proved not to be profitable due to the opportunity cost of keeping a large amount of capital tied up in the inventory of silver. The firm continued to make large quantities of Sheffield plate, but Boulton delegated responsibility for this enterprise to trusted subordinates, involving himself little in it.