There are many ways to place an estimate of a date of production for factory-made pottery or porcelain. Most involve the stamped or incised marks used by the company over its history, other marks were the result of international trade laws that are all well documented. Gathering these clues together is like solving a mystery, as each clue bring you closer to the answer. One such marking can tell us a great deal from one quick look, the “British Design Registry number”, or as some of us in the trade refer to it, the “Rd. Number.”
Here’s an example of what a Rd. Number looks like:
Since 1884, the British Patent Office issued a registration number like this when a design or mark was registered. As this is a British marking it also identifies in a glance that the piece is British. The purpose of this marking was to indicate the design was protected, that any attempt to copy it would lead to legal issues with both the company that registered the design and the government that enforced it. The length protection for the design of the item depended on the material used in its construction ; Ceramic 9items such as pottery and porcelain were covered from piracy by competitors for a period of three years.
What the numbers actually tell us is the first year the design was registered for protection. In this Rd. number above, “Rd. No. 56790,” indicates the mark was registered sometime in 1886. As that the protection of such a marking was only good for three years, it would give us a date estimate of 1886-1889 could be reasonably accurate, but it should be noted the design could have been in production a great deal longer than three years. With the chart below you will be able to determine the earliest year of production for any piece of English pottery or porcelain that carries a Rd. number. It should be noted that Rd. numbers can also be found on metal and glassware items, this chart applies to these items as well.